[urq] Oil temp falling on -88 MB quattro

[Jim Haseltine]

----- Original Message ----- 
From: "Johan H" <milisen at hotmail.com>
.
>
> The quattro has done this a few times the last two months. At first the 
> oil temp rises normally to about 100-110 degrees celsius. then all of a 
> sudden when I drove, the reading on the digital display fell down to 60 
> degrees (the lowest reading). When I drove a further 30 minutes the temp 
> jumped again up to the normal 120-130 degrees on highway.
>
> Does the urq have a thermostat on the oil cooler? Could the problem be 
> caused by this? If there is a thermostat, where is it located?

Yes it has a thermostat.
No it isn't causing your problem.
It's part of the alloy block that the oil filter and oil cooler pipes are 
mounted on.

The led bar gauges are pretty flaky - the oil temp on my MB used to reach 
about 90 and then disappear, a bit of testing showed that the thing would 
die within seconds if I grouned the thing. Fitted a different circuit board. 
Sounds like you have got an intermittant break in the connection between the 
gauge and the temp sensor in the bottom of the oil pump. Not surprising 
really, the even though the cable has a glassfibre heat-resistant sleeve the 
route it takes exposes it to a lot of heat, as it runs almost directly under 
the turbo and is clipped to the sump. Cable is pretty easy to replace, it 
plugs into the main loom just behind the right headlight.

Regards,

Jim Haseltine