Ok so before all of the snow hit, my deuce developed a case of the dreaded 'startup chirp'. The cold weather has put my enthusiasm to bed but I'm organising parts now in order to make a break for the engine bay and take on the job at hand.

Apparently the 3sgte is quite suceptible to getting a leaking exhaust manifold. The engine comes from the factory with a steel exhaust gasket, so the most common cause of the problems are:

1. Over tightening of the exhaust manifold bolts (thus pulling the soft alloy threads out of the head)
2. Warping of the exhaust manifold itself (causing 1.)

The implication of the problem is that instead of the exhaust gases making their way to the turbo, they leak out in the gap that forms between the head and the manifold. This gives you a reduction in power, loud exhaust leak noise, and also potential for poor running due to the lambda sensor not reading correctly.

In my particular case, the issue is characterised with a 'chirp' noise at startup, and the loud exhaust tones down as the engine area warms up - expanding the head/manifold in the process and closing the gap.

The fix for this problem is:

1. Have the exhaust mani skimmed on the mating surface to ensure a good tight seal.
2. 'Re-thread' the head so that the exhaust stud will hold correctly at the specified torque setting.

Stage 1: Planning the works

There are two quite good threads on this job in the mr2oc.com board:
mr2oc.com/showthread.php?t=158087&page=1&pp=30
www.mr2oc.com/showthread.php?t=310303

There seems to be a consensus that the best tool for the job is a solid threaded insert called a Timesert. There are other inserts available such as keensert and helicoil, however there seems to be quite a few success stories with Timesert in the MR2 world so that is enough for me to follow suit.

The Timesert installation is a five step process:

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Step 1: Drill the hole (or in this case) clean out the bad threads
Step 2: Counter bore the top of the hole (you'll see why in a minute)
Step 3: Tap the new thread for the insert
Step 4: Install the insert with the installation driver
Step 5: Screw in the exhaust mani stud

As you can see from this picture, the timesert is a metal sleeve that is threaded on the inside and the outside. It has a collar around the top, which is why you need to couter bore the hole. The collar serves to lock the insert in place between the head and the manifold so that it can't work its way out of there.


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Timeserts come in a wide variety of sizes, applications and materials (i.e. stainless steel, carbon steel, or mild steel) but it seems that the correct size for this particular application is a 10 X 1.25 (14mm length)

So step one is to buy a Timesert Kit (pictured) in the appropriate size

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In this case the kit is part number 1012, however it comes with 16mm inserts which are too long and would need to be cut down. Instead of doing this I opted to purchase some additional 14mm inserts in stainless steel which are part number 10122. I have also come across varying opinions on the Internet about the application of stainless steel studs in alloy heads. Some people say that they're a no no, others say that they're better than mild or carbon steel. Two things on this subject come to mind: Firstly if you have two different types of metals heating up, they can heat at a different speed, so possibly (or possibly not) the stud can tighten or loosen just by starting the engine. Secondly stainless steel is rust resistant, which is highly desireable when living in a damp environment with heat cycles. A stainless steel stud may look almost like new after 10 years of usage, whereas a normal stud could be corroded to hell and have to be broken off. On my old head, it had some of the studs replaced with stainless type and I did not have a problem, so I will go with that and see what happens.

I found out that Weurth in Ireland are the local Timesert distributor. I was in a bit of a rush to order the parts over the Christmas break however and Weurth were closed for the break, so I landed up ordering them online from Threaddoctor on ebay: http://stores.ebay.com/threaddoctor

In addition to odering the kit and stainless inserts, I also ordered a tap guide which helps to ensure that the taping process is done at the correct 45 degree angle.
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You could do this by eye quite easily if the motor is out of the car, but with the way I'm going to be attempting it with the motor in the car, this could prove to be a valuable investment.

One of the problems that I can foresee is that there will be alloy shavings accumulate in the hole from the drilling and taping process. It's necessary to remove that debris to do the job correctly and as I can't turn the head upside down and shake it, I have to come up with an extraction technique. I'm hoping that if I can magnetise a screw drive it will pick up the shavings, but sometimes that can depend a bit on the grade of alloy that the head is made out of. Another option is to use a vacuum cleaner to suck them out. This is quite feasible, however it's a bit inconvenient to try and get in there to make it work. Another option is using a wet bit of tissue on the end of a stick, poke it in and out and eventually all the shavings come out. I'm not sure which will work, we'll have to wait until I get to that point :)

The next par that I am looking for is a replacement stainless steel stud in the correct size/length..

Edit: my TimeSert kit turned up - it's not particularly large, so easy to store!

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Packed nicely and with instructions etc

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I thought the basic kit has everything you need, however the driver still needs a T handle. Luckily I had one in my tap and die set. I think they're only a couple of bob from the tool supplier anyways...

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One thing I noticed is that the tap guide seems slightly loose, but I'll see how that works out..

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Here are two timesert inserts Stainless (L) and Carbon Steel (R)

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Stage 2: Removing engine components

To get to the point of repairing the head I had to remove:

* Cross Brace
* Intercooler piping / Bov
* Inlet tract
* Mid pipe
* Downpipe
* Wastegate
* Turbo Charger
* Exhuast manifold heat shield
* Front engine hook
* Exhaust manifold
* Exhaust mani gasket (multi layer steel)

(Photos of standard engine Spanky??)

Stage 3: The repair!

Then I was left with something looking like this. The port was blackened with carbon soot and as the stud came out it dropped out some alloy threads also (you can see them on top of the coolant pipe).

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I put in a new stud, and it seemed to do up by hand.

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However when I removed it you could see small alloy particles.

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So it was definately time to bring on the drill, and in preperation I plugged all of the ports with wet wipes and then taped over them for good measure.

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It then occured to me that if one stud can strip, maybe more can also?! So I broke out the torque wrench, dialed in the sacred 38ft lbs measurement and went to work on the other studs. Good thing I checked because the other stud next to the bottom one came out also, and looked even worse.

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I have a 240v drill and a battery drill, I felt that the 240v would be a little wild so went for the 12v instead:

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The chuck on the drill was only just big enough to take the timesert drill bit and it took a few tries to get it to run straight and true. So on with a bit of WD40 (closest thing I had to machining oil) and I checked the depth of the stud hole to estimate how far to drill (don't want to clip any valves :D )

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The drill has multiple torque settings and I started with the minimum, this made the bit jam in the threads so I upped it a few settings. I had to do this a couple of times and in the end landed up at maximum torque and it was still jamming! I was contemplating using the 240v drill but I was really worried that it would go to far or oval out the hole creating a new problem. So I changed tact by running up the drill to full speed, then carefully edging it in mm by mm so that what it was cutting was the smallest amount at a time (like how a drill press works). This technique worked and I was able to cut out all the old threads and get the drill to the point where it was basically spinning in the whole without cutting any further. As you can see from this pic there's plenty of room for a battery drill in the engine bay. Amazingly this drill is fourteen years old - just goes to show you don't need to splash out on expensive tools to do simple jobs!

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The stud holes were then pretty crusty with shavings and because the engine is leaned over on a bit of an angle it's quite hard to get them out of the bore. Basically you can blow them out with an air line or try to clean them out with a cloth on a thin screwdriver, but we chose to pressure float them out of their with some WD40. This worked well and in no time they were cleaned up nicely ready for the next step! :)

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Due to the tight space in the negine bay, a hand mirror is useful to check your workmanship:

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Next step in the timesert kit is to do the counterbore cutting. I had done a test in a piece of wood and this was quite easy, however I wasn't sure how hard it would be to do in alloy:

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The design of the tool is such that it slots in nicely to the bore and holds it tight. Running up the drill to maximum rpm and applying pressure and it was able to cut the counterbore in less than a minute, and it came out great!

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After some more cleaning with WD40, it was a matter of moving on to the next step - tapping the thread.

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At this point some trepidation started to set in and I had visions of screwing up and having to order a bigger timesert kit, however I knew we had gone too far to turn back so I broke out the tap guide and got stuck in! Basically the tap guide is really only for the very start of the thread as once the tap is moving down the hole it has no choice but to go straight. I think that's why they tend to be smaller at the tip than in the middle as that helps you to not screw up the very start. Because I've tapped a few threads in the past and never used a guide before this made me feel a little uneasy that I could not see what was going on at the start, so for the second bore I just went by eye and left the guide off. I got the same result on both bores and if doing the job again I wouldn't bother with the guide, it's not really worth the extra money in this particular application as you can see what you are doing pretty well. In the case you were tapping a hole that you couldn't directly see then the tap guide would be very useful.

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Comes out looking pretty good!

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Next it's a case of screwing in the insert by hand (I used stainless inserts), putting some oil on the insert driver and then winding the insert home. The insert driver seems to get fairly well stuck in the insert pretty easy (that's why you need the oil), and so it means you have to tighten the insert in VERY tight in to the tapped thread. Once you have it tight enough it's then possible to loosen off the insert driver. If you insert driver is taking the insert out again then you either need to tighten it in more, or you forgot to put oil on the driver.

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At this point the camera ran out of batterys, however what I found was that the insert was not completely flush wiht the flange that the manifold bolts to. If it was raised it would be a problem, however it was recessed in to the counterbore. I don't think this will be a problem however as when I put the new studs in to the inserts, popped on the new gasket and manifold, they passed the torque rating no problem. First 10ft lbs, then 20ft lbs, then 30, then 38ft lbs.

I can say that after doing this job there is nothing more satisfying than hearing the 'click' noise from the torque wrench at 38ft lbs :)

One thing to consider before starting is to make sure you have the right tools for the job. The first torque wrench I had only starts at 40ft lbs, so I had to go back to Halfords and buy a second wrench that had the right torque range for the job at hand.

I found this page of the BGB was very handy for getting various torque settings etc:
http://mr2.ie/mr2/bgb/mk2/mechanical/10.html

Final note: I would definately use Timesert inserts again, I found the kit to be very professional, well thought out and with clear, concise instructions. The only thing that is missing really is the T bar handle for winding the tap and I reused one that I have from another tap and die set.

Also a very big thanks to my moy bien amigo Augusto who taught me some new Spanish swear words and helped out with each and every step. Doing this job for the first time is much easier with two people and makes it a bit of craic too!

I am liking the way you are presenting this article Quandry KC+

Me and Spanky are about to tackle the same thing on his two we are going to replace the manifold.
PS Don't be shy with the turque setting

Quandry wrote:
One of the problems that I can foresee is that there will be alloy shavings accumulate in the hole from the drilling and taping process. It's necessary to remove that debris to do the job correctly

Use a small convex mirror to see into the tapped hole, shine a light onto the mirror to light up in the hole. Best way of making sure its free of debris is to blow the hole out with a compressor. I can drop you down one with the blow tool (oh behave you lot) when you are doing the job if you want.

Fair play Ray, I'll get the mani etc off hopefully this weekend and see what is at play.

ricky2 wrote:
Me and Spanky are about to tackle the same thing on his two we are going to replace the manifold.
PS Don't be shy with the turque setting


Exactly, not sure if the problem is the same as Quan had. I get a loud rattle when the car is cold which slowly gets better and disappears as the exhaust heats up.

I have a replacement mani, and both gaskets to go on, hopefully without having to do the work to the studs.

Torque setting would be good though


@Rick: I have been horizontal all christmas with the flu and chest infection but I have everything I need now. We can pick a weekend in Jan sometime to have a go at the work.

Spanky wrote:
Rick: I have been horizontal all christmas with the flu and chest infection but I have everything I need now. We can pick a weekend in Jan sometime to have a go at the work.
No sweat mate just not the weekend with the 15th I'll be 21+vat_+vat then

I'm all done! you're next Spanky

Write up and pics updated above.

Great progress

Its great that Spanks has the same to studs striped
We will be doing his when he is back from sunning himself

Well done guys KC'd on the double, but one is for Augusto.

Quandry wrote:
I'm all done! you're next Spanky

Write up and pics updated above.

No worries and we will take pics along the way ... making sure the camera is charged

I'm in two minds whether to use the inserts or the larger studs that Ricky2 posted about a while ago. The larger studs option is one less component in each location, which sounds like a good thing to me.

Do you thinkt he inserts are a better job for any reason?


Also, how many do you have left? and how much to rent your kit? and is your experience also for sale (I have bacon, sausage and Haribo )

Spanky wrote:
Also, how many do you have left? and how much to rent your kit? and is your experience also for sale (I have bacon, sausage and Haribo )

The Spanky breakfast is worth the journey alone, well I survived anyway

Spanky wrote:
Quandry wrote:
I'm all done! you're next Spanky

Write up and pics updated above.

No worries and we will take pics along the way ... making sure the camera is charged

I'm in two minds whether to use the inserts or the larger studs that Ricky2 posted about a while ago. The larger studs option is one less component in each location, which sounds like a good thing to me.

Do you thinkt he inserts are a better job for any reason?


Also, how many do you have left? and how much to rent your kit? and is your experience also for sale (I have bacon, sausage and Haribo )

The only thing that comes to mind is that if you use a bigger stud you may need to drill out your manifold hole also. Maybe that stud Ricky posted has different sizes on each end so you don't have to do that?

I have plenty of inserts left and you're welcome to borrow the kit. I can help you out if needed but am a bit low on family brownie points for a day off up in Belfast at the mo.. So I can post the kit up to you - if you and Ricky want to have a go there, or I can help you on a Saturday in Dublin whichever suits you

One thing to note though is that I'm only halfway through the job. I have my old mani off while I get my good one machined dead flat. If I put my good one on a piece of glass it can rock with about 1mm of run out. The bgb says that manis with more than .2mm of run out should not be used! so if I were you I would get your replacement mani checked and decked to 0 run out. After I get to refit my good manifold I will be able to see if the inserts have loosened off at all (hopefully next weekend). That may be a good time to make a call on the insert vs stud decision

I have a spare manifold here which I bought when I thought I had a cracked one on the car. I will check it to see what sort of tolerance there is on it.

The studs risky posted are larger at the head end and the same size at the manifold end so you still need to modify the thread in the head but everything else stays as is. I'm not sure if you need to cut new threads or just screw the bad boy in.

In honesty I think both methods would be as good as each other, just the modified stud option has one less process to do i.e. putting the inserts in.

I am heading off on holidays today so it will be the end of May or June before I get a chance to do this.

I will probably call down to you to get the kit rather than getting you to post it. The decision then is, do we do it at yours or bring it home to do it some other time. We can get something arranged closer to the time.

I'm looking forward to getting this fixed 'cause I hate the sound of my car when I start it. It sounds like someone rattling marbles in a can and I always think that other will think I don't give a shit about the car

I will get in touch when I get back from holidays

With the bigger stud you would still need to drill/tap the head, but yes it has one less item to go wrong.

As a side note, I put my car back together today, took me 5 hours to put on the turbo/downpipe, exhaust pipe, whole inlet system, change the oil, top up the coolant, take it for a solid test drive and check everything over. So far so good! no start up chirp and everything seemed to be in good shape. Once I get my mani sorted I get to do it all again.... I'm hoping that as I will be in practice I can do the whole take apart and put back together in 5 hours this time

I think we will be better off with your system then we can be sure of it.
I'am glad it worked out for you

I'll trust the judgement of you more learned brother on this guys. if the inserts work on Quans car then they will def work on mine.

@Ricky: the only decision is the location of the work .... do we go to Dublin and get done and drive home or do we do in NI????




BTW: I fly out tomorrow, currently sitting in Rad Blu in Dublin airport - the holiday has started and I return in a lotta lotta weeks I will be on site but perhaps not that regularly and 5 hours behind you lot - but I was always a bit slow.

I do have my webcam with me so if you are on skype add markspenceni to your contact list and I might give you a video call from Miami beach or somewhere equally sickening

Spanky wrote:
I'll trust the judgement of you more learned brother on this guys. if the inserts work on Quans car then they will def work on mine.

@Ricky: the only decision is the location of the work .... do we go to Dublin and get done and drive home or do we do in NI????




BTW: I fly out tomorrow, currently sitting in Rad Blu in Dublin airport - the holiday has started and I return in a lotta lotta weeks I will be on site but perhaps not that regularly and 5 hours behind you lot - but I was always a bit slow.

I do have my webcam with me so if you are on skype add markspenceni to your contact list and I might give you a video call from Miami beach or somewhere equally sickening
I think you have my skype Id. Have a good one and don't drink to much (you have give me your keys I could have done it the first time I was board) Have fun


EDIT You do know if we take it to Dublin you'll need to let it cool before you start work

you know instead of all that specalist equipment i do sell M11/M10 exhaust repair studs for £8

M11 one end so you can repair the head, and Normal M10 coming out where the manifold bolts to.

Tim
TB Developments

tbdevelopments wrote:
you know instead of all that specalist equipment i do sell M11/M10 exhaust repair studs for £8

M11 one end so you can repair the head, and Normal M10 coming out where the manifold bolts to.

Tim
TB Developments
I'am I Right in thinking you don't need to re tap the threads for your studs?

well you just drill and run a M11 tap down the holes. that means its tapped straight into the alloy of the head like standard over having to run the helicoil setup which i know can be expensive for the kit.

Tim
TB Developments

Well we (myself and Ricky2) got the exhaust studs replaced on my two and it all back together. Now she starts without a rattle. A summary of what we done is here:

Engine bay at start


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engine bay with pipes and exhaust heat shield off


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The hole where my manifold and turbo used to be


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looking back into the engine, guess where the manifold was blowing out


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The manifold and turbo sitting on the ground while the work is done.


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Original exhaust manifold gasket blackened on one end where the studs were loose


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In short we:

1 Remove the X brace
2 Remove the air filter to turbo main hose, both hoses connected to the inter cooler and the air line from the wastegate actuator
3 Remove exhaust mani and downpipe/CAT heat shield
4 Disconnect the oil and coolant conns to turbo
5 Remove all nuts on downpipe (both ends and support bracket) and exhaust manifold
6 Remove dipstick tube - to avoid damage
7 Remove turbo/manifold/wastegate mechanism in one lump (one heavy lump!!!)
8 Drill out and re-thread to M11x1.25 for all studs which are lose.
9 check that mani is straight enough as it can warp at the connection to the head
10 ensure everything is cleaned off
11 Put it all back together again using new gaskets on mani to head, mani to turbo (if you disconnect them), oil feed and coolant feeds to turbo.

Sounds easy but will take a full day at least.

Problem areas:

1 getting to the nuts holding the oil connections on
2 breaking nuts on the hot side of the turbo due to the heat 'welding' them and/or previous workers over-tightening in place
3 being advised to 'gut my CAT' only to discover it wasn't made of porcelain

Due to no3 I now no longer have a CAT (now replaced with a Japspeed pipe) and so have potentially carried out my first true performance modification to the car - SHOCKED!!!

All in all a tricky job, but using the repair studs from TB Dev. is painless - once you get to that stage. I only takes about 15-20minutes (of Rickys time) to thread and screw in the new stud. Then the real fun begins as you try to get everything back together again without have bits left over aka un-intentional weight reduction.



A massive big thank you to Ricky2 who not only saved me a fortune by doing the work with me but also taught me a hell of a lot about the layout of the engine and how awkward it actually can be to work at.

I would ask that you all KC him at least once on my behalf.



If anyone needs to carry out this job I have two of the studs which I intend to return to TB soon, so let me know ASAP. I also have the tap needed for the threads which anyone on here is welcome to borrow.

well done Spanky! kc for the efforts and writeup - and Ricky also

MODIFICATION, MODIFICATION!!, your on a slippery slope young man.

Next month it will be an EBC, your own design I hope and all of a sudden the credit card will be maxed and you will have 4 billion horse's.

Turned to darkside, indeed you have, Skywalker.

Well done lads, KC's when I get home and the buttons appear again.