oil in water expansion bottle?!

[Debbie.gsd]

Hi!

Yet more problems with my Surf. Recently had a new head fitted. Seems ok since been done, but the problem I've got at the moment is oil contamination in the water expansion bottle and around the radiator cap. Thought it was possibly a problem to do with the new head. When I called my mechanic, he was baffled as to why there was oil in expansion bottle, and the engine oil level was normal, he checked the engine, said that was running ok, didn't seem to be a problem with the new head.Then he checked the transmission oil and that was low, well I had not long topped up the transmission oil myself as it was very low, so he's saying it's transmission oil in the water which means a problem with the radiator and the pipes that cool the transmission box. He's saying that I will probably need a new radiator, but I was wondering if there was anything else we can do, before I go paying out for a new rad. Would a radiator flush help at all? I'd read that the oil could possibly be left from the earlier problem with the cracked head? Any ideas / suggestions of what I can do?
Thanks,

[Tallyman]

It's possible that the ATF oil cooler in the base of the radiator has picked up some rust and is allowing the ATF fluid and the coolant to mix. If you've got the red coolant then the red ATF fluid won't really show up except as an oily mix on the top of the water.

If the rad is gone then yes, get it fixed ASAP as you don't want the gearbox & torque converter to get contaminated with water. That could cause real expensive problems.

[BUSHWHACKER]

Maybe give the rad a good flushing first, refill with water then run engine up to temp, without driving it, and check again after it has cooled.
Don't waste any anti-freeze when topping up before the test, save wasting it.
If you can still see signs of oil in the water, I'd say replace rad.

[Debbie.gsd]

Hi! The oil that's showing in the expansion bottle is black, thick gunk. It has no smell, which engine oil has. The water level rises and stays high. I've emptied the bottle, cleaned it, filled it to the right level, and in a week the oil has returned, altho the water level is ok at the moment.

[NiftyNev]

Here is a suggestion.Disconnect and plug the transmission cooler pipes.Allow as much transmission fluid as possible to drain from bottom of radiator.Seal one hole for trans cooler with a suitable fitting and connect a pressure tester to the other fitting.Remove the rad cap.Apply 20 PSI pressure to the trans cooler and see what happens.If ok it will maintain the pressure.If not then there is a leak and you may even see it bubbling where the rad cap fits.If it's leaking then do not drive because if coolant get in transmission then that, as stated, will be expensive.

Neville

[Koi]

I would out of peace of mind have the engine pressure tested as well, seen this black thick oil in the expansion bottle before and it wasn't ATF.

[Hilux]

Oil

Hi l have seen it so many times when the cooler on the autobox leeks into water the fluid goes "PINK". AS you are saying it is a black oil showing, it may be some of the left over contamination from getting the head done in the first place. Who done the head job for you was it "Rob" near "Prestatyn" hope l spelt that right if so he certainly knows his stuff.

[Linda]

. The water level rises and stays high. I've emptied the bottle, cleaned it, filled it to the right level, and in a week the oil has returned, altho the water level is ok at the moment.

You need to flush the whole rad not just the expansion bottle to remove any oil left over from the head (if thats the problem).

[Debbie.gsd]

Hi! Thanks everyone for the advice. Will put these suggestions to the mechanic when he comes.
No it wasn't Rob who did the head for me, the mechanic is a mobile mechanic but he does all the jobs for the Car Centre (who Rob used to do all the jobs for) on all his imports, Surfs and Pajero's etc, so he deals with Surfs a lot! Especially changing the heads!
Hi Linda....I will be flushing the whole rad first, the reason only the expansion bottle was cleaned, was to see if the oil returned and how quickly, and whether it coincided with the level of the ATF dropping, but the ATF doesnt' seem to have dropped. I think, as suggested, it is probably residue from the original head problem, so will try flushing rad.
If there is a leak, and coolant gets into the transmission, what sort of initial signs/problems will there be? The Surf is driving well, but when idling the revs seem to go up and down and it feels like it wants to take off while waiting at junctions.