Engine overheat and fumes

[Jono]

We took our van to Spain and Portugal last summer and drove in temperatures in the high 30 s upto 42 degrees. The van generally went well if running marginally hotter with with the gauge just above 1/2 way. When driving in the mountains however on some unrelenting hills upto 6,000ft the gauge inevitably rose. Although I took it easy and stopped regularly to let the engine cool, on one section there was nowhere safe to pull over so I just had to keep going. When I did manage to stop with the gauge nudging 3/4, black fumes came out of the engine vents. At first I thought we were on fire but a quick check through the number plate flap with the fire extinguisher handy showed this was not the case. It was not possible to empty the van on the roadside to check the engine bay so I just let the van cool down and carried on.

When I could stop and check the van properly there were no signs of any leaks nor anything obviously amiss and there was no noticeable drop in oil or coolant levels. No further problems were experienced on the trip of over 3,000 km ( other than the squeaky heater fan finally packed up )

So what was the cause ? Only thing I can think of was the oil got too hot and it's time to fit an oil cooler, oil temperature and pressure gauge ? Maybe a chicken switch too ( 2nd fan speed cut in soon after stopping )

Would welcome people's views

1990 LHD Westfalia California pop top 1.6td JX

[colinthefox]

Others may well correct me if I am wrong, but I seem to remember reading somewhere that the JX engine is only rated for a relatively short time at full power because the turbo will overheat.(But I haven't been able to find a reference to quote for this) We Have been over a few of those Spanish/Portuguese passes and they are seriously long! Perhaps this could be your issue. There should be a supplementary coolant pump and temperature switch for the turbo as well. Are you sure that was working OK?

[Jono]

Temperature switch for the turbo ? Where's it located and what does it do ? The only supplementary coolant pump I'm aware of is the little electric one that comes on to keep coolant circulating for a while after the engine is turned off. That's working fine, at least after the engine's turned off. Is it supposed to work at other times too ?

[dave friday]

Hi Jono,my guess on the black smoke is that some oil from the cam cover had dripped onto the very hot exhaust manifold /turbo ( the turbo on my van gets to 825 deg c !! ) the auxiliary water pump is controlled by a temperature switch ( on the water pipe that comes off the side of the cylinder head ) that comes on independently of the ignition switch.
The same switch turns a blower on that blows onto the turbo ( only on syncro models I think )
Water temperature ,we have found that some of that "stop smoke stuff " lowers the water temperature !!

[RogerT]

As far as I remember the auxiliary water pump is not relevant to this, it maintains coolant flow after the engine is switched off, and if memory serves me correctly, that’s to prevent damage to the head? Whatever it’s for, jono, you’re right about it’s function.

How was the engine after the smoke incident? Any change in any of it’s characteristics? And did the black fumes come out while the engine was running or after you switched off (if you can remember...)

[Jono]

Hi all

No, no change in the engine characteristics afterwards. Not sure if the fumes were coming out when the engine was running, nothing noticeable when going along. Just pulled over, turned off and noticed the fumes. Worse out of off-side vent which you would think the opposite if oil had dripped onto the exhaust manifold, though that that could still be the case. Unless it's been missing all the time I've had the van ( 5 years ) there's no blower to cool my turbo and pretty sure there's no obvious space to mount it ( I have all the tinware fitted around the engine and turbo ) Perhaps this could be a mod to do ?

[RogerT]

Fan for the turbo was only on the syncro I think, to cool it as it worked hard in the absence of passing airflow as you crawled along. I've no idea what your problem was. No trace of oil leaks anywhere? Maybe just carry on crossing your fingers and keep your breakdown cover current... in the absence of any more detailed and time consuming/expensive investigations.