ZX TD inlet manifold gasket

Dave1 · Post by **Dave1** » 09 Jun 2007, 18:35

Whilst trying to solve the possible leaking matrix issue (still waiting for Bars to work after about 70 miles

) I have another issue. There appears to be an "oily" substance at the rear of the engine. This has been the case for a good while and I notice there is a bit of a weeze when the turbo comes in. If you have seen my recent post it refers to a smell of what I believe is coolant (only when the heater is tunred towards the hot postion). The smell could be the substance on the exhaust but I do not think it is as I can only smell it when heater set to on, not generally under the bonnet.

Anyway, is it possible this substance is coming from a leaking intake manifold gasket and if so, is the gasket isolated to inlet only rather than shared with the exhaust. (Haynes is a bit vague here but my model is XUD9TE). If it is shared with the exhaust, does the exhaust itself need removing or is there enough room to undo the manifold alone and let it drop a bit?

jeremy · Post by **jeremy** » 09 Jun 2007, 19:11

I can't see what's in the inlet manifold to leak. Ok it'll be oily inside due to leakage and fume re-circulation but there's not much oil there and its not under any pressure.

On our non-turbo one I found the rocker cover bolts had worked loose and oil was dripping down the back on the engine onto the rear mount. Also oil leaking at the front is pushed round the back by the airflow - which makes leaks in the vent pipes at the front difficult to trace.

The front vent pipes are worth having a look at. I had to put clips on a couple where the rubber had hardened and they didn't grip tight. Cured a leak!

Dave1 · Post by **Dave1** » 09 Jun 2007, 20:05

Hi Jeremy,

I was kind of thinking it may be that circulated stuff. I know on the large intake pipe there is a join and that always gets a gathering round it. I suppose until I strip a few bits off I will not know for sure but in view of the weeze noise it may be worth looking into the gasket anyway.

jeremy · Post by **jeremy** » 09 Jun 2007, 21:16

The source of the wheeze is probably the manifold/intercooler gasket - which is probably what looks like liquorice - rubber round section like an enormous 'O'ring.

Post by **philhoward** » 09 Jun 2007, 21:18

Am i thinking of something else, but do i recall an issue with the intercooler to manifold seal on the "on top" intercooler XUDs (405/306/BX and ZX)? Like they fail...

fastandfurryous · Post by **fastandfurryous** » 09 Jun 2007, 21:53

You may have the same issue with a combined inlet/exhaust mainifold gasket as I've had with an XUD9TE in a 405. They only seal once. despite being made of pressed tin, and looking like they're re-useable, if you try and use them again, they don't seal. The oil in the inlet tract then gets blown out by the turbo, and it makes a right royal mess everywhere.

My advice would be to use the manifold gasketing system used by earlier engines. These employed a separate exhaust and inlet gasket system, and are much better.

Dave1 · Post by **Dave1** » 10 Jun 2007, 18:26

fastandfurryous wrote:You may have the same issue with a combined inlet/exhaust mainifold gasket as I've had with an XUD9TE in a 405. They only seal once. despite being made of pressed tin, and looking like they're re-useable, if you try and use them again, they don't seal. The oil in the inlet tract then gets blown out by the turbo, and it makes a right royal mess everywhere.
My advice would be to use the manifold gasketing system used by earlier engines. These employed a separate exhaust and inlet gasket system, and are much better.

That sounds like the problem. Whilst I have never removed it, I know on a previous thread someone said they are made of a type of plastic on later models although I think it was a Xantia he referred to. It was suggested it sounded like a reed valve

I still do not know whether I have a separte gasket or not but it is certainly higher up the back of the block so would ideally only hope to have to replace one if possible.

Jeremy,

I think I know the part you are talking about. It is like an oblong piece that sits in a recess. I have replaced this once as on cleaing the intercooler I noticed it had "grown".

Here is another question which you may be able to answer. Where is the air taken from for the vents. Is it all taken from the part under the wiper in the bulkhead, be it hot or cold at first. The reason I ask is if not, then it may be possible that the oil is creating the smell when only heater vent is open.

jeremy · Post by **jeremy** » 10 Jun 2007, 22:00

Yes the heater / vent air intake is the grill behind the bonnet. There should be a seal between the bulkhead and the bonnet which is intended to keep the fumes in with the engine but how effective this becomes with the passage of time and small accident repairs I don't know.

What I do know is that the washer bottle lid is useless and its very easy to get the washer water and detergent to flood and this can be clearly smelt inside the car.