22 replies to this topic

[dennisb]

My 2000 MPi is overheating. 'Usual' story, needle goes up then steam piles out.

It's had 2 new tank caps on, new temp sensor, new 88 deg thermostat, sensor harness mod done, new fan relay, fan works with 12v put through it, connections are all clean and sound. No coolant leaks, no air pockets ( i don't think) and also had coolant flushed and refilled at 1:1 mix, twice.

Might have missed something there...

A friend has wired me a direct connection to the fan in the meantime.

I'm now absolutely stumped now as I can't think of anything else that may be causing this - any ideas anyone?

Thanks,

Dennis

[mykweb]

My 2000 MPi is overheating. 'Usual' story, needle goes up then steam piles out.

It's had 2 new tank caps on, new temp sensor, new 88 deg thermostat, sensor harness mod done, new fan relay, fan works with 12v put through it, connections are all clean and sound. No coolant leaks, no air pockets ( i don't think) and also had coolant flushed and refilled at 1:1 mix, twice.

Might have missed something there...

A friend has wired me a direct connection to the fan in the meantime.

I'm now absolutely stumped now as I can't think of anything else that may be causing this - any ideas anyone?

Thanks,

Dennis

ola

Had the same issue last week

Mine was a combo of an airlock and fubard stat


Swing over if u want a fix it day?

Mike

[dennisb]

Nice plan Mike - Thanks for the offer!

I've got another stat on order to try and see how it goes. Might also look into that pipe/radiator flush stuff and see how easy it is too.

I know the problem you see, I just don't know the cause... the fan just won't kick in... annoying how stuff just happens sometimes

[dennisb]

Forgot to say there, the car's getting some work done inside the next 2 weekends, then after that it's with me at Selkirk, so I couldn't see you for at least 3 weeks. I'll see how the forum goes and my wee schemes....

Still like to come say hello one day and maybe have a wee fettle with the cars though, so I'll give you a shout when the free weekends are back

[JonnyBMX]

I just had this same problem, turned out the thermostat had stuck shut, very easy to replace. has sorted all my overheated out nicely

[dennisb]

thanks for the reply, but I don't think that's the problem here as I'm now on my second new thermostat so I think it's very unlikely that I had 3 broken ones on the trot. I have a few more spares and it is a quick and easy swap, so I might try another anyway just in-case. Cheers man.

[dennisb]

Mike, after us talking and your advice the other night there, I pulled the fuse with the fan on (using the override switch thing) and it stayed on. I also disconnected the switch/cable to put back as factory... then the car overheated again with still no fan kicking in. Stuart (the guy who fitted the switch) said he knew about possibly interfering with the set-up and put an earth in to work it not more 12v somewhere. (hope that makes sense!)

Since it OH'd again, I put the switch back in to keep me safe.

ps. the OH was with the coolant system checked for air and/or leaks plus had a new therm. and cap on the tank.

[dennisb]

Update on this problem... Car still overheating and fan never coming on. To date I have done the following:

New 88 deg thermostat (x3)
New fan relay
New Expansion tank cap
New coolant sensor
Sensor loom mod done.

Still totally stumped by this one. I was asked by a fellow club member to earth a point on the relay to see if the fan kicked-in (pin 85 or 95, sorry can't remember) , which it did. The guy said that this means that everything beyond the relay is fine and that the problem must be either a cable fault between the ECU and the relay or a fault in side the ECU - does this sound correct?

Another problem I have is no electrical meter or knowledge of how to use one, so I am limited in what I can test or repair.

[mykweb]

allright dennis

see you still having issues.

Have you actually tryed to swap out the expansion tank. My so called new one would not seal correctly with about 10 caps due to the threads on the tanks.

Mike

[dennisb]

No not tried that yet Mike, but I will soon. It's a really simple job by the looks of things. I had to move the tank to check the earth header underneath a few days ago. When I have the money for a tank it'll be the first thing I get.

[Juju]

Mine kept doing the same thing last year. Same model. I went through 2 head gaskets, stats, and expansion tank lids.

Turned out the fan was shorting on the front panel, which started off the whole episode. Fuses kept blowing. Once we'd re-insulated the wiring, changed the fuse (again) flushed through, re-filled, we found a slight leak in the 3rd tank cap, so it carried on over heating.

Changed the tank cap again & all fine. If you've built up masses of pressure, then it might be worth changing your cap again, but if the fan's not coming on, check the fuse (no 15?) and the fan's wiring.

[dennisb]

Thank Juju.
Fuse is fine and so is the fan wiring.
It's just the damn thing isn't getting the signal to start because forcing a start from the relay works.
Totally stumped.
Looking at tanks just now. Hopefully get one after the Thistle Run...

[new_zealand _minis]

just take the thermostat out ./ put blanking sleeve in . shuld solve it !!

[dennisb]

Relative novice here NZM, what would a blanking sleeve do for me?...

[andymini12]

Have you tryed water pump as well, i would change that and see.