Engine Cooked? Give me the bad news...

[Deeceer]

Not sure yet but I might have just cooked the engine in my 1998 T4. It's an AAB 2.4L 5-cyl normally aspirated diesel.

Strange howling noise suddenly under the bonnet at highway speed, goes away at low revs. Turn round and try to ease it home then suddenly there's massive engine drag and that's it, pull over. Under the bonnet there's coolant leaking from around a heater hose and a black plastic valve(?) assembly partway down. Tow truck time (RACQ).

The temperature gauge never moved from its usual position so please don't ask, I feel bad enough about it already. After seeing the leaking coolant I even switched the ignition on to take another look at the gauge - normal.

The towie tried starting it to drive it onto the truck but said it wouldn't start and there seemed to be no compression. I was in the cab of his truck while he was doing it (he sent wife and me in there straight away because we were on a narrow shoulder of a 110kmh highway and his job was just to get us and the vehicle safely off the highway) so didn't hear it turning over. I haven't tried restarting it since we got it home.

What has me kicking myself is there was a very slight noise that came and went last weekend but there was reason to suspect the accessory belt slipping and I would have had my mechanic look at it last week but he was away. I was going to see him tomorrow (sob!).

Ok, so has anyone an idea of the bad news if indeed the engine has overheated to the point of cooking? How much can a rebuild cost? Or is a reconditioned engine better value?

I have no experience whatsoever with overheating in diesels but if it has cooked, I'm surprised it didn't seem any hotter than normal under the bonnet and there was no unusual smell.

[Deeceer]

Update: There's little doubt there's serious problems - I just checked the coolant tank. It's empty of coolant and coated inside with oil...

[h100vw]

If it were me, I'd fill it with water and see what it does. Could be a a bad waterpump or something?
Gavin

[Deeceer]

I did wonder about the water pump earlier on.

Right now though there's oil in the coolant tank but no coolant/water apparent on the engine oil dipstick. I'd rather keep it that way if it means preventing the motor from going completely bad.

[Deeceer]

Update #2 - after having a read around on the web and finding a description that matches the symptoms, could it be a blown a head gasket where the engine oil is at higher pressure than the coolant which has caused oil to blow into the coolant but not let coolant leak into the engine?

Or are there other areas where engine oil can blow into the coolant?

Anyone know what kinds of costs involved in rectifying problems like this?
Does the engine have to come out to take the head off? (I'm thinking not - just the radiator and some odds and ends?)

[h100vw]

I'd call Jmac, Jimmy and get his diagnosis. He is often through the GC. He would be the best one to tell you what's what.

Is there a lot of oil in the header tank? Even the tiniest amount looks like the end of the world. soak it out with some kitchen roll and see if you get more after running it for a while.

If it has an oilcooler on the filter mount, they have been known to fail but that usually takes years to happen.

Head gaskets can fail in many places given lots of different symptoms. A proper mechanic should be able to diagnose it quick and easy.

Gavin

[Deeceer]

Thanks for the suggestions. I'm not sure how much oil is sitting in the bottom of the coolant tank (and can't look now - the van's stranded in the street outside and it's dark!) but there's absolutely no coolant in there and the inside of the coolant tank looks like an oil filled bomb has gone off in there. It's like oil was suddenly belched into it and spattered the insides. I also now suspect the loss of power (that I first described as sudden engine drag) just before I pulled over was the compression going away.

I have a German mechanic who's not only very good but also adores VWs and I'll be dropping by his place tomorrow. Of course, his adoration of VWs doesn't mean he works on them any cheaper...

I'm just keeping my fingers crossed at this point that I've not actually cooked the engine and warped the head.

[van quish]

If it is an iffy waterpump (like mentioned) thats pretty serious, if that goes the cam belt will slip!! It does soud like the head gasket has gone as the water has gone and there is oil where the water shold be - if it was mixed it could be the cooler. Hope the head aint warped matey and it just needs a light skim.

[05gtwagonman]

Hi Deeceer, and sorry to hear of your pain.
Let me first make clear that I'm no mechanic, and I agree that you should talk to Jimmy (jmac) he was just very helpful to me, can't recommend him more...

My t5 has ended up at Austral under a stat wty claim (just bought 2nd hand from a dealer) sitting in the workshop with it's head off... I thus can confirm that the head can be totally removed without removing the engine from the car. A quick idea: a comment in passing that the type of work happening on mine would cost at least 2.5k, probably more...
Mine has had no mixture of oil or water to any degree, and it's still going to be a massive job. With yours' I'd certainly hope that it's 'just' the head gasket- that would actually be one of the better results. It certainly bodes well that the temp didn't skyrocket, but you may still end up with scored bores any any number of other significant issues. A loss of compression isn't all that likely to just be the head gasket I think... No one is likely to know the extent of the damage until they get in there... Jmac will almost certainly be cheaper, just be sure that you have a space for him to do it, or that he has access to a space, as it will take several days even if it just a skim and gasket... You want it out of the weather... Try and find out if anyone is wreaking one and what the engine is worth, just so you know what the upper limit should be to continue with a repair...
Good luck.

[Deeceer]

Jmac was out today to take a look and administer the last rites. Unfortunately the engine is cactus - water pump went and took a whole bunch of stuff with it. There wasn't a tooth left on the cam belt. Suspicion is that the water pump wasn't replaced by the previous owner when the belt was. Jimmy's now on the lookout for a used engine.