Oil cooler finished, now got coolant leak!

[IFFY100]

I'm baffled as to why I have a coolant leak after doing the seals. It seems to be the oil cooler or could also be the turbo pedestal (doubt it). Only thing I can think is that I reused the cooler bolts and maybe they aren't to be reused? Everything else was new. And I double checked the seating of the purple seals too

 

[Jobsworth]

Common for the little aluminium tube with a green O ring each end that bridges the two intake manifolds to leak if you haven’t replaced it

 

[IFFY100]

Thanks for the reply. I have replaced with a new piece and that is not leaking.

 

[Jobsworth]

Thanks for the reply. I have replaced with a new piece and that is not leaking.

Sounds like you are going to be taking it apart again then. Sorry.

 

[IFFY100]

Yep. And I was very very careful. I just can't understand what I could've done wrong. When you did the seals, what torque settings did you apply? I'm also thinking that my torque wrench maybe out of calibration??
About the seals now, which ones should I reuse? I know not to reuse the copper stretch bolts, but what about the seal behind turbo, pedestal (top, bottom?) mani gaskets??

 

[Jobsworth]

All the gaskets must be replaced. If you’ve reused the turbo pedestal upper or lower gaskets they are likely culprits

 

[IFFY100]

Nothing apart from 3 manifold bolts and oil cooler bolts were reused. I really didn't want to do the job again so bought everything new.

 

[IFFY100]

And I only reused the mentioned parts because merc are not good at part locating

 

[unclebuck]

If the oil cooler is coming off again get new seals again dont reuse incase they got pinched. Get the new set of oil cooler bolts, the numbers for them are in my thread.

When the cooler comes off you need to clean the mating surfaces on the cooler and the block, any grit will compromise the seals.

When fitting the seals a little lube will help them in, when tightening the oil cooler up remember there is a pattern you need to follow, this is a good video to watch how the oil cooler is bolted on, change the subtitles to english as its in german.

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there is the little o ring that goes onto the end of the heat exchanger pipe did you replace that with a new one?? it may have fallen off.

here:

intake manifolds, oil cooler seals | Engine

Thread update later tonight. You tease ! I’m still going to bed early though ;)

forums.mbclub.co.uk

you can see the exhaust cooler pipe seal at the bottom on the packet and fitted, if you dont have this fitted then its a leak point.

Just replace all the bolts with new, they dont cost much

 

[unclebuck]

oh one other thing.. if you are taking the turbo off and the pedastal off, then get another set of gaskets as you have crushed them, everytime i had to take mine off i just grabbed new gaskets, off ebay merc newcastle. I just wasn't prepared to take a chance with a "new crushed or pinched" gasket or seal.

put some pictures up also makes it easier for us to help.

oil cooler bolts tighten to 10Nm

 

[BlackC55]

Before you take it apart again. Use a cooling system pressure tester to locate the leak just incase its something else. Damaging the inlet manifold gaskets is easy to do.....

 

[unclebuck]

Buy a new calibrated torque wrench!!

 

[IFFY100]

If the oil cooler is coming off again get new seals again dont reuse incase they got pinched. Get the new set of oil cooler bolts, the numbers for them are in my thread.

When the cooler comes off you need to clean the mating surfaces on the cooler and the block, any grit will compromise the seals.

When fitting the seals a little lube will help them in, when tightening the oil cooler up remember there is a pattern you need to follow, this is a good video to watch how the oil cooler is bolted on, change the subtitles to english as its in german.

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Accept third party cookies

there is the little o ring that goes onto the end of the heat exchanger pipe did you replace that with a new one?? it may have fallen off.

here:

intake manifolds, oil cooler seals | Engine

Thread update later tonight. You tease ! I’m still going to bed early though ;)

forums.mbclub.co.uk

you can see the exhaust cooler pipe seal at the bottom on the packet and fitted, if you dont have this fitted then its a leak point.

Just replace all the bolts with new, they dont cost much

Thanks for the replies. So far I had cleaned the mating surfaces and used very fine 600 grit paper to lightly clean any residue. I did not use any grease to ease in the purple seal as it seems to have sat in no problem. But this maybe was not pushed in properly? What type of lubricant is good to use? No joke, is ky jelly a good idea? I renewed the heat exchanger seal and the gasket at the back of the heat exchanger. Although I didn't use the pattern in the video, I used my own pattern when loading the cooler. Basically I went criss Cross from end to end. I wiil defo buy new bolts.

 

[IFFY100]

Buy a new calibrated torque wrench!!

I'll see if it can be professionally calibrated.

 

[IFFY100]

Before you take it apart again. Use a cooling system pressure tester to locate the leak just incase its something else. Damaging the inlet manifold gaskets is easy to do.....

Cracking idea and I will do that. Any advice on a checking device to use?

 

[IFFY100]

oh one other thing.. if you are taking the turbo off and the pedastal off, then get another set of gaskets as you have crushed them, everytime i had to take mine off i just grabbed new gaskets, off ebay merc newcastle. I just wasn't prepared to take a chance with a "new crushed or pinched" gasket or seal.

put some pictures up also makes it easier for us to help.

oil cooler bolts tighten to 10Nm

I'm just ordering all bolts just now. I tightened the bolts to 12nm. I will fire pics here. I noticed the leak when the car was in the air and I wad topping coolant in a stone cold engine. I put coolant in the resvoir and it started dropping under the car. Also in terms of coolant, which brand and type should I use that can be mixed with the original mb stuff? My coolant is blue?

 

[unclebuck]

I'll see if it can be professionally calibrated.

matey a teng tools wrench isn't that expensive, i bought a couple for working on mine.

 

[unclebuck]

is the pipe from the thermostat to the radiator back on correctly?

 

[unclebuck]

I have pretty much gone as far as I can with advice, I am not a professional Mechanic as I have said before, I learned what I needed to to work on my car and just bought everything new as shown in my thread.

Personally if it was me everything would come back off and I would do it all in stages, making sure that each bolt was new and ready to fit (laid out with respective gaskets etc)
And do a single job then double check it, make a list of things on a note pad and tick it off including torque the bolts, this is what i did.

So when everything was clean i did this and wrote it all on a note pad, this way I had to follow the rebuild list, this is just a small example of how i went.

Oil Cooler

1. Check mating surfaces on oil cooler and block mount are clean and free of contaminates.
2. Fit new seals to oil cooler
3. Place oil cooler into position and insert bolts using a torx driver to a gentle hand tightness
4. Set torque wrench to 10Nm and follow pattern to tighten down ( i had this on my note pad)
5. Once tightened go around and double check make sure to tick this job off before next job.

Inlet manifolds:

1. Check both sets of manifold faces for contaminates also the engine faces, wipe clean if need be and chaeck again
2. Check both Inlet manifold gaskets for any damage, if damaged or crushed then replace do not use
3. Check bolt card of position of old bolts ( old bolts were inserted into a piece of cardboard and marked as to where they came from/number)
4. Check thermostat has new gasket fitted and no damage or contaminates to mating face.
5. In your piece of cardboard that has the old bolts inserted replace each one with the new bolt required ready, put old ones into a bag and put out of way so as not to get mixed up.
6. Make sure coolant bridge pipe linking manifolds is clean and no damage to either seal, insert into manifold holes
7. Fit gaskets to manifold faces and place on block faces, insert one bolt in the top middle of each manifold to hold it in place, do not tighten down just screw it in a few threads
8. insert all new bolts to hand tighten, once all in follow pattern to tighten to below the full toruque setting, once happy set wrench to correct setting then go around again tightening to full Nm setting

I would suggest taking pictures of everything putting them up and perhaps the indy's here can help you better.

Its hard to give advice on something thats not in front of you

 

[IFFY100]

matey a teng tools wrench isn't that expensive, i bought a couple for working on mine.

Don't like the idea of wastage. But need a 1/4 torque wrench anyway, so will buy that.