thermostat housing and high oil temps- related??

[matt_corradovr6 0]

had thermostat housing replace a while back by what i thought was a good garage but seems that they were a bit well shit. when having gearbox put back after diff blew, reliable mechanic said thermo housing looked on way out. could a dodgy thermostat/housing cause the heat exchanger used to help coool the oil to not function and the oil get too hot (114-118 degrees)?? how hard is it to cahnge the housing and thermostat?? what have i got to do?? thanks guys and nice to see a few rados at spring festival! :salute:

[Kevin Bacon 5]

A partially jammed thermostat caused my oil to sit at 114 degrees cruising at 80!

 

I replaced it and fitted a mocal and now the oil rarely goes over 100.

[matt_corradovr6 0]

how easy is it to replace thermostat??? how to drain coolant etc? how do you get 'stat off?? would a mocal be neccessary? tahnks

[Kevin Bacon 5]

Try the stat first and decide from there if a mocal is required.

 

To remove the stat you need to:-

 

1) Strip the gearbox side of the head of the coilpack etc

2) Drain the coolant by unscrewing the block drain plug and pulling off the rad bottom hose.

3) Seperate the stat part of the housing from the main assembly.

4) replace stat

5) replace other stuff

6) Refill with G12+ via the radiator top hose.

7) Drive car for 20 mins.

8) Top up in the morning.

[matt_corradovr6 0]

when you s`ay strip the gearbox side of coil etc, will this mean resetting alarms etc?? is it quite easy??? thanks

[Funkster 0]

It shouldn't affect your alarm - you don't really need to take the battery out (although it does give you more room if you do).

 

Kev, you mention separating 'stat housing from the rest of the housing but not removing the rest of the housing from the block - I couldn't get a tool in to undo the 'stat housing bolts without removing the whole lot. What did I miss?

 

Taraa,

--

Olly

[Kevin Bacon 5]

Alarms? Nope. You just need to get the coilpack out of the way and possibly and it's all easy stuff!

[2cc 0]

Just trying to recall exactly how its oriented. I think you can just get at the stat hsg screws (2) (from front of engine) with the temp sens shroud removed, not sure whether the fan motor gets in the way though as I'd taken mine off. Like kev says, remove the coilpack. The water pipe should move enough for you to remove the stat hsg without taking off the whole assy.

[Funkster 0]

There's 3 bolts on the stat housing - if I could get my stupid frikkin' good-for-nothing bentley manual to run I'd post a piccie. I can't so I can only add that there are two short ones and one longer one, all with their 5mm socket heads facing away from you as you look at the housing from the front of the car.

 

fwiw,

--

Olly

[2cc 0]

couldn't remember if it was 2 or 3, all my stuffs at home. might look later on

[dr_mat 0]

From what I hear, the thermostat and housings tend to be all getting leaky/weak at around this sort of age, so it's worth swapping them. 118 degrees on the oil is a little high at 80 mph, and it *could* indeed be related to the thermostat, but you're more likely to see weird behaviour on the water temp first - that will be your biggest clue to thermostat problems.

[Guest]

From what I hear, the thermostat and housings tend to be all getting leaky/weak at around this sort of age, so it's worth swapping them. 118 degrees on the oil is a little high at 80 mph, and it *could* indeed be related to the thermostat, but you're more likely to see weird behaviour on the water temp first - that will be your biggest clue to thermostat problems.

 

118° is fine on a VR,

[dr_mat 0]

I agree, but: my VR rarely gets above 114 degrees on the oil.

 

I agree it's nothing to worry about, 118 is well within the acceptable range, but it's *slightly* more than I'd expect to see at a constant 80mph.

 

** edit - But then, I note that the original poster said "114-118" and didn't say how fast he was cruising, so I'd actually say that's "perfectly normal" then..

[Kevin Bacon 5]

118° is fine on a VR,

 

No it isn't. Something is wrong if it's running that hot on a part throttle cruise.

 

Golf VR6s run nothing like that hot, so 118 is NOT normal for the VR6 engine.

[dr_mat 0]

What do Golf VR6s run at at constant 80 mph cruises then, out of interest?

 

What we're saying mostly though, is that 118 is "normal for an unmodified Corrado VR6". Whether it's a design flaw is another matter.

[matt_corradovr6 0]

i get 118 degees at bout a staedy 90- 100 mph. would like it to run cooler but i do think that the stat wasn't swapped when housing apparently was changed but as i said mechanic that swapped g box said the housing looked iffy but i haven't been able to check myself yet.

[dr_mat 0]

118 at those speeds is perfectly fine. Or at least "normal". It's up to you if you think it's worthwhile adding an oil cooler.

(Note that VR6s run fine in much hotter countries than ours without additional oil coolers...)

[NickRStorm 0]

What do Golf VR6s run at at constant 80 mph cruises then, out of interest?

 

My 150K mile Golf VR6 runs about 104 at 80mph & 112 at 100, but my 80K mile Storm seems to run 6 degrees warmer at each speed. Also noticed the Golf never budges from 90 degree water temp under any cicumstances, but the 'rado is all over the place. About to change thermostat to see if it makes it any more stable.

[dr_mat 0]

Interesting. Would be more interesting if we could work out if this was a real difference, or a difference in the reporting of the gauge.

[NickRStorm 0]

Interesting. Would be more interesting if we could work out if this was a real difference, or a difference in the reporting of the gauge.

Mmm, I suspect the 'rado guage is a bit flakey, but the water temp does seem generally higher than the Golf in that the thermo fan comes on far more often & earlier.

[NickVR6 0]

Hi, spect you've read my cooling issues! For info i had a golf vr for 2 yrs, on 120k with original everything! It rarely got over 102 at 80 and water never budged from 90, EVER! Stat went but gauges all shot through the roof in seconds so nocked it off and coasted, replaced and back to normal.

 

Other half has had a vento vr for 4 years. It never budges from 90 on the water temp either, and you just cant get the oil over 102 doing anything, even caning the jublies off it in the summer (hope shes not reading this!).

 

My corrado vr runs at 106 at 50 not touching the throttle, and 110/114 at 80/85mph. Water temp varies from 90 to 100, and seems to bare no relationship to how its being driven or at what speed. Oil allways drops to 102 idling though.

 

Dont think i will ever be happy with this after the golf and vento. I think the mocal is the way forward. ANY CHANCE OF A GROUP BUY ON THESE FROM SOMEONE??????? This seems to be one hot topic (pardon the pun!) :roll: