Slightly Gross (PRV Crud)

addo · Unread post by **addo** » 16 Apr 2011, 07:52

Apart from looking like something pushed out by a small canine, this solid plug of "brown stuff" was clogging one of the intermediary hoses between trans cooler and the main coolant lines. It took serious pressure to expel it (my local town water is quite good for backflushing engines)...

Not good for the trans, either! Does anyone have a source/brand for the coolers (other than PSA, who want a king's ransom)? Same cooler as on 4HP-14 Xantias and early 406 four-pot autos.

Regards, Adam.

Unread post by **CitroJim** » 16 Apr 2011, 08:46

Oh yuk!!!!

AndersDK · Unread post by **AndersDK** » 16 Apr 2011, 21:50

That would be the "hamburger" style oil cooler.
2275.23 - found on Xsara, Xantia, 306, 405 & 605(4HP18) with 4HP14.

It looks VERY similar to the standard hamburger found on the earlier XUD's under the oil filter can.
You may have a sharp look on one of these to check if they fit on the tomato.

PSA ref 1103.C9 or 1103.G3 - found on almost any XUD.

addo · Unread post by **addo** » 17 Apr 2011, 00:12

Hi Anders, thanks for the extended list of options. Do you know if they corrode inside, or is the "silt" entirely from other sources?

Deanxm · Unread post by **Deanxm** » 17 Apr 2011, 10:16

In my experience its silt but mainly rad seal, the coolers are rather low down and the transmission cooler is the lowest part of the system on the xm at least, coolant flow ist great to it and if any sealant has been added over the cars life it will all end up in the cooler, it is very rarely flushed out on coolant changes either.
The main issue with them is the pipe fittings seem to corrode and you end up with nothing left to connect the hoses to but if there is no water in the gearbox or oil in the coolant just give it a good flush through with a hose and carry on, no point throwing money at it for no reason.

D

AndersDK · Unread post by **AndersDK** » 17 Apr 2011, 11:58

We have seen a few instances on early XM V6, where the cooler rots internally, mixing the coolant with engine oil.

The engine oil then turns brown - not grey - and the coolant slowly thickens up shifting to the same brownish colour.

Its not a common problem though, as we always use at least 1 : 2 coolant/water mix over here.
This prevents corrosion on the cooling side.

Over my 40years with cars I've never experienced any problems with the standard rad sealer products utilizing ginger powder.
These products do their job well as promised.
And smells good too.

Of course if you add 4-5 bottles - that may create problems ...

addo · Unread post by **addo** » 17 Apr 2011, 12:09

I have exactly that problem with my blue 605's engine oil cooler:

Andrew here, put me onto the cause - corrosion of the cooler internally as you describe - it makes sense that oil at 60PSI would escape into water at 14PSI rather than the opposite (at least while the holes are tiny). Good way to ruin hoses made from unobtanium; rotting them from the inside out.

Just going to bypass and flush it for now; the blocked trans cooler hose was from my recently purchased parts car and it made me concerned about what may be the situation with others.

Cheers, Adam.

AndersDK · Unread post by **AndersDK** » 17 Apr 2011, 12:39

Donno "down" by yours -

But it may be a cheaper option modifying to a standard air/oil cooler located under the rad.
The oil filter can sits happily on the engine block "as usual", if the center extender is unscrewed.

EDIT : the hamburgers are in fact standard parts. Here is an example :
http://www.flex-a-lite.com/auto/html/sa ... pters.html

Unread post by **CitroJim** » 17 Apr 2011, 19:01

All this talk of hamburgers and tomatos... I thought I'd accidentally stumbled onto a McDonalds forum Anders

Some quarters say never use any coolant additive when there's an autobox cooler in the picture. I found the cooler well and truely blocked on my Old V6 and that may have contributed to the demise of the 'box..

Mind you, the cooling system had been dosed with K-Seal and something else that looked like Portland Cement - it was a mess...

Personally, in an auto, I'd only use Forte Stop Leak and nothing else... I'm sure the Forte stuff would be fine..

In fact, your "blue mayo" looks very much like Forte Stop Leak Adam...

addo · Unread post by **addo** » 17 Apr 2011, 21:28

I wouldn't put it past some of our specialists to actually use cement powder!

It's oil in there, Jim - the reservoir cap's rubber seal ring is sticky and swollen from contamination.

While we're talking cooling systems and slight modifications, has anyone seen a cheaper version of the Parker tube beading tools, than the kits around USD$400?

Cheers, Adam.