Exhaust Manifold Gasket

[Simple]

Last year, my Citroen C8 2.0 HDI engine noise was a tad too high and sometimes there was a smell of diesel fumes after starting (when cold). I could not locate the source visually, so I used an elastic pipe with one end stuck to my ear and the other hovering around the engine until I found the source, which was a small leak in the exhaust manifold gasket. It was not much, so I ignored it.

For the past few months I was getting DPF failures, later the car gradually developed a high screeching noise after 1800 RPM (sounds like a bad bearing) that receded to a high pitch whine at high speeds, add to that power was not at its best either.

First, I excluded the serpentine belt and the pulleys/bearings associated with it by removing it, starting and revving the engine. At that stage, I was convinced that the noise is either from the Turbo saying his last prayers (since it starts around 1800 RPM) or from the timing belt and associated pulleys/bearings like water pump, tensioner etc... I replaced the timing belt, the water pump, the tensioner and the idling pulley (they were due anyway), but the noise is still present.

I was not in a hurry to fix it, until the time for the annual test arrived!!. I then investigated the Turbo, but it was in good form. However, on a cold morning, I started the car and I could see black water bubbles coming out between the manifold and the engine body (near the timing belt) where I identified it earlier.

I stuffed the hole in the side of the manifold (probably the gasket has disintegrated) with “Gun Gum†and built an extra ridge reaching the edge to prevent the exhaust force from blowing it out.

1- The screeching noise is “unbelievably†gone.
2- Engine power and responsiveness have improved.
3- The DPF failures are gone (obviously, the sensor was reporting lower pressure than expected).

I know this is a temporary solution, which will not last. So I bought the Exhaust manifold gasket for my engine, it was 6 Euros at the dealer, but he did not have it, so I bought Elring from a parts shop.

Now comes the difficult part which I was trying to avoid; fitting the gasket!!! I have reasonable experience in car mechanics, and have changed head, inlet manifold and exhaust manifold gaskets for other cars before. However, I have never done that for this engine with the very limited space.

I would appreciate advice from those who may have changed exhaust gaskets for this engine without removing the engine. My concerns are these:

1- The disassembling of the manifold and associated parts (like Turbo and EGR) and precautions or preparations?
2- Any further requirements such as gaskets of other components that need to be removed in the process?
3- I am expecting to find that the engine and manifold surfaces at the leakage point have been deformed/pitted and may need to be filled by welding, is this needed?, are there easier ways like filling with Gun Gum or any other past/ compound?.
4- Any other recommendation.

Thanks in advance.

Simple.

Edited January 3, 2018 by Simple

[paul.h]

I would try a message to coastline taxis. He has not been on here for a few weeks but may respond to a message. The service box procedures do not say how to do this job but it gives a time of around 5 hours. For the 2.2 hdi it gives about 10 hours but for that needs the engine removing.

[Simple]

Thanks Paul,
You are right, the Service Box documentations are a little short on procedure this time. I don't have the intention or the tools to lift the engine, so I will evaluate access to the various parts before the attempt.

  

It is a little too late to write to coasline taxis as we intend to have a go at it today (if the weather improves; it has been windy and raining all night). I wanted to start before the weekend in case I need to buy unexpected parts.

[Simple]

At the latest stages before taking the exhaust manifold out, we hit a show stopper (seized nut and hex bolt), some welding may be necessary to force them out, but we have to prepare replacement parts first.

 

So, due to late hours, we had to reassemle and resort to using Gun Gum to block leakage temporarly.

 

Hopefully we'll have another go some other weekend.

[paul.h]

I hope you had not got a long way in to the job before finding this. I have used a nut splitter to remove seized nuts.

[Simple]

My sons were carefully working on the car; they actually reached near final stages before rolling back. It was a great learning exercize for them, nevertheless.