D2 TD5 Oil cooler alternatives

[reb78]

After finding that my oil cooler on the TD5 has been disconnected from the coolant system and blanked off at the rad and the heat exchanger, I've been looking at getting the gear together to put the proper system in place. I presume there was a leak in my system that a previous owner has botched in this way.

The repair kits are only made by Britpart (as far as I can see), so I am reluctant to waste my money there. Someone is sending me a complete (non-holey) oil cooler unit from an engine they are breaking so I will have that to hand.

However, the thought of having that oil cooler inside the side of the block seems like an odd idea to me. Has anyone ever fitted anything external that works as a heat exchanger like this:

http://www.ebay.co.uk/itm/plate-HEAT-EX ... %26ps%3D54

If plumbed in in the correct direction would it not do the same job and also be a damn site easier to change if faulty and also keep an eye on for leaks?? What are your thoughts? The one pictured is just something I picked out as an example, there may be something more suitable out there. Would flow through the heat exchanger be sufficient (especially when cold)? Perhaps it would need a thermostatic bypass?

I should add that it has run without overheating since we have had it (the last year) - that is going by the guage though, so it may be running hotter than normal but i get the impression the gauge tells you cold, tepid, hot and overheat.

[Aragorn]

The VAG group use this sort of thing as an oil cooler/heater:

http://www.biotuning.co.uk/images/068117021B.jpg

Its essentially a small heat exchanger, which sits between the block and the oil filter, and has coolant piped thru it. Something like that might be retrofittable?

I guess the first question is are you only worried about overheating?

If so, adding a radiator style cooler with a thermostatic takeoff plate would work better than the coolant driven versions, but it can only cool.

OEM's usually use oil to water coolers as it helps to get the oil up to temperature faster, IE it acts as an oil heater when the engines cold, then an oil cooler when its hot.

[reb78]

Good points Aragorn.

I hadnt thought about the heating aspect, but you are right. I think The coolant based system is best as it gives both advantages as you point out.

My thoughts behind an external exchanger are multiple

1. If/when it leaks, it is easier to get to, inspect and change if needed
2. I can add it now without dismantling the side of the engine
3. I'm not restricted to repair kits from Britpart!

I guess my worry is the effectiveness of any bolt on compared to the original. Do you think something like the VAG version will provide as much cooling and heating as the original system? In a way, does it matter - like i say, it doesnt appear to have overheated (yet!) running in its current state without the exchanger piped in, so surely this can only be beneficial?

[Aragorn]

The vag cooler seems to cope upto around 300-350hp on a 2.7 Twin Turbo petrol, at which point things start getting a little too hot for comfort without upgrading.

I'd say based on that, and given looking at them, they look pretty similar in size, most coolers you'll find will happily keep a TD5 engine within tolerance.

[gadget]

After VIN 2A736340 the oil cooler wasn't plumbed in to the coolant via the steel pipe around the rear of the engine.

It was blanked off with a very expensive rubber bung PYB500040.

[reb78]

After VIN 2A736340 the oil cooler wasn't plumbed in to the coolant via the steel pipe around the rear of the engine.

It was blanked off with a very expensive rubber bung PYB500040.

Oooo. The plot thickens (mine is a 54 reg, so one of the late D2s).

So how did the system work, or was there no oil cooling from that vin onwards?

[gadget]

From what I've been able to figure it seems that the wash over from the block was deemed sufficient for the oil cooler and it was blanked.

They left the pipe running around the rear of the engine but not plumbed in to anything. As that pipe fed the EGR cooler i suspect they might have ditched that too, but i've never seen one in the flesh to check.

Do you have the EGR cooler?

[reb78]

The EGR has been removed, so i suspect the cooler is gone too. That might explain why the pipe has gone.

[gadget]

I'm reasonably sure that the egr cooler isn't there as standard and that what you have is may well be stock

I've tried to find a coolant diagram showing the plumbing for the later set-up but no luck.

[reb78]

I've tried to find a coolant diagram showing the plumbing for the later set-up but no luck.

That would be handy as i cant really figure out how/if the oil cooler i think is fitted in there works!

[gadget]

The cooler fins on the inside are washed by the coolant in the block.

give me a minute and i'll break out my shiny one a post a photo of the insides.

[gadget]

Here you are.

Outside

The brass bolts are banjos and feed the oil from the galleries into the aluminium heat exchanger inside.

Inside

The heatexchanger is immersed in the coolant in the block.

The pipe on the outside would let a small amount of coolant out to the radiator via the egr cooler.

Does that help?

[reb78]

Yes. Very much. Thanks.

So that cooler sits in a coolant chamber in the block. I dont know how else i thought it would work (it was a bit of a eureka moment then)!

[Team Idris]

We bought a housing+cooler repair set as the edge of the ally housing had corroded badly and cooler was leaking. We thought about blanking the engine block off, so as a start I drew the bolt hole positions up on CAD. If it's any use, that drawing should still be in the CAD archive here on LR4x4.