508 HDi Oil Cooler issue

Glenn

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Fellow Frogger
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Jan 4, 2004
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Two reealted questions:
I have read threads about oil changes and emphasising the need for the "right" oil which I believe is "low ash". What happens if this is not used and how quickly will issues emerge?
What would cause an oil cooler to collapse internally?

Thanks

Glenn
 
Stacked plate oil coolers are a series of thin aluminium conduction plates with turbulent passages from end to end pressed in, and the whole stack fused together. It's like a Dagwood sandwich. Hot oil passes around alternate plate passages and coolant on the others. The plates perforate if the coolant is not sufficiently inhibited. You can see the effect with old aluminium saucepans and kettles. Don't take risks with aged or insufficiently dosed coolant. These units are used on engines designed for cars.

Ash is a product of oil combustion. It eventually poisons catalytic converter and clogs particle filters, exhaust gas recirculation and even the air inlet manifold and ports. Some bleeds past turbo bearings. Some bypasses piston rings and is burnt. Some comes from crankcase ventilation, and is fed into the engine via the turbo. In each case it enters the exhaust system. It can be expensive to get cleaned out if build up affects performance of components.

The only oils PSA recommends for these engines is low ash (low SAPS) C2 grade. PSA issues a specification for oil. The sulphated ash content of the recommended Total product is 0.69%. Magnatec Professional C2 (a trade product) is 0.7% It goes up from there. Penrite C2 is 0.8%. Petrol engine oils are higher. The more oil you burn, the sooner you need maintenance.

Oil ash isn't the same as carbon byproducts of fuel combustion, which are burnt off at filter regeneration.
 
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Thanks Seasink I appreciate your explanations.
Glenn
 
Just remember too that the SAPS ratings of ACEA C2 and ACEA C3 oils are the same.

There is a very slight viscosity difference leading to a very slight fuel economy improvement by using C2 oils - otherwise C3 oils are the same for your DPF. Both C2 and C3 have the same Sulphated Ash requirement.

C3 oils are quite often easier to find at more reasonable prices in places like SuperCheap.

To answer your first question though, you need to have been using a C2 or C3 rated oil to prevent the DPF from suffering - how quickly this becomes a problem though will come down to driving style and vehicle usage. Certainly lots of short city trips are more difficult for the DPF than regular freeway based trips at 100km/h.

Cheers

Justin
 
Has your oil cooler died?
I had to replace mine on my 2.0hdi 308 (same motor I believe). I started to get a bit of oil in the coolant until one morning on starting it filled the coolant bottle with oil and it spilled out the top. I managed to find a genuine cooler/filter housing out of Germany for around $300 (half the price of what I could find it elsewhere) and replaced the whole unit. It was a time consuming job as it is in a tight spot under the bonnet but haven’t had a problem since. I am not sure what caused it to go as I always use the right coolant and replace it before it gets too old. It did make we wonder how many people have scrapped their cars because they think it’s a head gasket when the oil appears in the bottle.
 
Has your oil cooler died?
I had to replace mine on my 2.0hdi 308 (same motor I believe). I started to get a bit of oil in the coolant until one morning on starting it filled the coolant bottle with oil and it spilled out the top. I managed to find a genuine cooler/filter housing out of Germany for around $300 (half the price of what I could find it elsewhere) and replaced the whole unit. It was a time consuming job as it is in a tight spot under the bonnet but haven’t had a problem since. I am not sure what caused it to go as I always use the right coolant and replace it before it gets too old. It did make we wonder how many people have scrapped their cars because they think it’s a head gasket when the oil appears in the bottle.

So True. You learn something new every day. I'm so glad to have seen this as if I had ever seen oil in the coolant I would have gone straight to the head gasket. How do you do a compression test on a diesel - pull out the glow plugs ?

Thanks for sharing.

Cheers

Justin
 
That is exactly what happened LukeG. It is actually my son’s car and he bought it second hand so no real known history of servicing. I had assumed from seasink’s comments that 5he coolant g
had not been changed regularly.
 
Aluminium corrodes and pits easily in hot water. The plates are thin. The only retardant you have on the water side is the additive in the coolant. The oil side can corrode also, from some of the ingredients in oil brews.
 
That is exactly what happened LukeG. It is actually my son’s car and he bought it second hand so no real known history of servicing. I had assumed from seasink’s comments that 5he coolant g
had not been changed regularly.
Coolant doesn't get replaced regularly anymore by "official" service schedules.

It is a pH test-based replacement — that is, it's only replaced if it fails a pH test.

Private ownership/servicing is another matter, of course.
 
I'd hope the coolant would be changed when the timing belt is changed.
If you don't change the water pump at the same time, you're probably wasting your time.
Of course some people don't even bother changing their timing belt. :rolleyes:
 
I'd hope the coolant would be changed when the timing belt is changed.
If you don't change the water pump at the same time, you're probably wasting your time.
Of course some people don't even bother changing their timing belt. :rolleyes:
True that - however with (I think) a 180,000km/9 year interval, that is not very often either :)
 
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