W638 Vito won't warm up

[E240estate]

2002 W638 2.2 108CDI Vito.

I've just bought this van with suspected head gasket failure. Pressure tested and leak (gas) tested the system and both tests indicate HG OK.

Drove it for the first time this weekend, about 15 miles in total, up some steep hills, along a national speed limit road, gauge didn't move off 40 for ages and hit 50 once.

Lukewarm heat out of the heater the whole time, but never getting really hot.

I've proved gauge works, as I have had the van up to 80 degrees once, after about an hour of revving it up on the drive.

I'm guessing thermostat stuck open unless anyone has any different experience of this fault?

Question is, where is the thermostat located and what's involved in changing it? Guessing on the back side of the engine somewhere as I can't locate it from peering into the engine compartment.

 

[grumpyoldgit]

See if this thread from the US forum helps

2000(V) Vito 108cdi temperature reading problems - Mercedes-Benz Forum

 

[Benzowner]

Sounds like thermostat to me, they are usually located on the top of the engine where the large top hose from the rad meets the engine block. In the good old days of working on mini engines, the housing was held on with three bolts, but these modern engines may be a little more

 

[BTB 500]

Lukewarm heat out of the heater the whole time, but never getting really hot.

I've proved gauge works, as I have had the van up to 80 degrees once, after about an hour of revving it up on the drive.

I'm guessing thermostat stuck open unless anyone has any different experience of this fault?

Check the radiator top hose - if it starts to get warm straight after starting the engine then the thermostat is stuck. Normally it would be cold until the thermostat opens. Can't help with the location on a W638 I'm afraid.

 

[E240estate]

Vito W638 Head Gasket now gone - coolant into cylinder

Well after a couple of months of driving, finding the thermostat missing, replacing that, and a small external coolant leak around the head gasket area, in total it's taken about 1,000 miles of driving for the HG to fail completely.

Last week whilst driving the unmistakable white smoke, dramatic coolant loss, temp gauge all over the place and cold heater meant that there is now no question - I need to replace the head gasket.

I've done one on a VW engine before. Can I do this one with the engine in the van? I understand it will probably be easier with the engine out but I just don't have the facilities to do that, I'll have to work outside on the drive.

Also for the gasket itself, is it best to use a genuine Merc part or are there better aftermarket ones better placed to take up the inevitable variations in thickness/flatness which will result from taking the thing apart? If so, what are some reputable manufacturers?
Thanks

Oh, and to answer my own question about the thermostat - it's front left of engine, behind the oil filter housing, not too difficult a job with the front grille off

 

[E240estate]

No too many responses - has anyone on the forum done a 2.2CDI head gasket before, or am I in unchartered territory?

If it's a first I will see about putting some pictures of progress up. Shall I start a new thread?

Got all the plastic covers off so far and got the injectors/ clamp bolts in a nice bath of carb cleaner, penetrating oil and biodiesel before attempting to undo.

And as it turned out I had to chip off a fair bit of black carbon build up from around the injector tops so I needed to do the injector seats anyway.

Still be interested in any tips anyone has for changing a 2.2cdi HG though...

 

[BTB 500]

You'd probably be better off starting a new thread as the title of this one bears no relation to the info. you're after now. Good luck with it though!