swanman 0 Posted November 15, 2003 Well I thought it was fixed! Same old symptoms. Have changed the coolant a number of times, ensuring that there were not air locks. Filling up through the top rad hose etc. Go for a drive the coolant temp seems quite normal, but the engine temp seems to slowly go up and then rise well above 110 even touching the max of 160 after about 10-15 minutes. Some related observations though. The car drives well regardless. When I drive my car home from work, so it has been standing still for 8 hours plus, the engine temp registers 160 as soon as I start up and stays there until I get home. Is it sill an air lock? Is it the sensor? Is it the water pump? I have recently changed the coolant as it was a mucky brown when I bought it a few months ago, maybe the water pump internals are corroded. The car has always driven well and I never checked the engine temp readout closesly before I changed the coolant so I cannot say if this was going on before. :?: Quote Share this post Link to post Share on other sites
Guest Posted November 15, 2003 Well I thought it was fixed! Same old symptoms. Have changed the coolant a number of times, ensuring that there were not air locks. Filling up through the top rad hose etc. Go for a drive the coolant temp seems quite normal, but the engine temp seems to slowly go up and then rise well above 110 even touching the max of 160 after about 10-15 minutes. Some related observations though. The car drives well regardless. When I drive my car home from work, so it has been standing still for 8 hours plus, the engine temp registers 160 as soon as I start up and stays there until I get home. Is it sill an air lock? Is it the sensor? Is it the water pump? I have recently changed the coolant as it was a mucky brown when I bought it a few months ago, maybe the water pump internals are corroded. The car has always driven well and I never checked the engine temp readout closesly before I changed the coolant so I cannot say if this was going on before. :?: i have a similar reading on my C too, i think it has to be the sensor, because i had it serviced and the guy reckons everyhting is fine. However mine goes upto 110, then settles for a bit, and then shoots too 142, 150....but if i flick the MFA to a different reading and then go back to it, it goes back to 113, 118.........so its definitley the sensor cos the engine cannot cool from 150 to 110 within 2 secs. let me know what you find out and if you do replace the sensor and if it works. cheers m8 Quote Share this post Link to post Share on other sites
dr_mat 0 Posted November 15, 2003 The MFA does a rolling average temp reading, as I understand it, so it shouldn't be too badly affected by a sudden, completely stupid reading. But if the sensor is consistently wrong, there's not much the MFA can do but add the numbers up and display the result... In both your cases I'd definitely blame the temp sensor. Quote Share this post Link to post Share on other sites
h100vw 0 Posted November 15, 2003 Swanman, I'd go for re-racking the plug on the sensor. There could be a bad connection there causing a high resistance and a false reading. We are talking oil temp arent we. Sometimes bad earths can cause strange readings. I had a MK1 Golf and stuff used to change when turning on the headlights, I never did find the problem. The readings only changed a few degrees though, not 50. Have a look round the engine and make sure the earths are good too. I missed your previous post, what engine have you got? Gavin Quote Share this post Link to post Share on other sites
swanman 0 Posted November 17, 2003 I have a vr6, Golf. Where is the sensor for the oil temp? Quote Share this post Link to post Share on other sites
h100vw 0 Posted November 17, 2003 Looks like it is on top of the oil filter housing. Although, I think VRs have a remote filter. The wire should be Green with a Balck tracer down it. Gavin Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 17, 2003 I think the sensor might be on the back of the head like the 16V. The sensors on the oil filter housing usually monitor oil pressure, could be wrong though. Kev Quote Share this post Link to post Share on other sites
swanman 0 Posted November 25, 2003 Took it to an auto electrician today. They seemed to think that the sensor was ok but there was a problem in the circuitry somewhere, too much hassle (i.e. too expensive) to fix. Will ask about it at the VW dealer on my next service. Thanks to everyone. Quote Share this post Link to post Share on other sites