Hi folks. I have a 1.9 AAZ engine in my VW T25 transporter. When I bought the engine to replace the old JX engine, the head gasket was gone. This would have happened in another car. I got the head skimmed, replaced the gasket and put new stretch bolts in and torqued them as per the manual. I drove the van on and off for about 1000 miles and it started developing an overheating problem. I replaced the fan switch cause I didn't think the fan was working. The gauge got up maybe 3/4 of the way when it first overheated going up a long hill. I stopped before I thought it got critical though. It was fine on motorways mainly but then on a trip across the country (4 hour drive) it started overheating on the motorway on the way back. I pulled over, discovered the auxiliary electric pump was not working, and put the heaters on full to keep it cool, which it did. When I got home though, just as I was coming in the gate, clouds of white smoke smelling of coolant started coming out of the engine.
To give a bit more background, the oil pump I used in the engine swap was not good. The pressure light would be on at idle. I didn't replace it although I had one to go in. The engine would cut out after sustained motorway driving too when I put the clutch in. I have taken the head off now and it's in getting pressure tested and reskimmed but from what I can tell, the overheating was only happening on the one cylinder. There was evidence of melting happening on the head there. Some small pock marks which can be seen in the pic. I cannot afford to have this happen again so I'm trying to do as much research as I can to prevent it and I'm replacing both water pumps and the oil pump and taking out the radiator to flush it properly. I will replace the thermostat too. What might have caused this to happen? Would it be worth getting my injectors tested in case it was running lean?
Here's some pics...
Thanks!
Ross
Yes, have the injectors tested. It would be from running rich, not lean that would give you problems though. It could also be a bad spray pattern.
Thanks for the info. Just a thought... Could liquid or dirt in the head bolt holes have caused the bolts to not tighten fully and hence cause the head gasket to blow? I didn't clean out the bolt holes when I put the head back on. An oversight on my part.
Yes to a degree. Part of the reasons why manufacturers spec a low torque number followed by x degrees of rotation is to minimize variables like damaged threads, dirty threads, different lubricants on the threads etc.
I think the fact that your coolant pump wasn't working is the real issue.
Yeah but the main water pump seemed to be working fine, and everyone is telling me the electric water pump is not essential anyway. That's one of the things that's throwing me. Is the block clean enough there in that pic by the way?
My monitors all screwed up, I can't see any details in pictures so someone else will have to determine that. Either way it's not a bad idea to run a tap down them and to blow them dry. Some people coat the head bolts with oil (lightly) some put them in dry.