205 GTI overheating - ideas/suggestions please

[TheExcession]

Hi,

I've got an H reg 1.6 205 GTI with about 125K on the clock.

When I got it I noticed occaisionally the oil temp gauge would limb a bit, this hot weather has really made things worse.

Today after about 15 minutes of normal driving the oil temp needle was straight up and the 'Stop' warning light came on.

Strangely the water temp needle doesn't move much at all.

Now I've put a new thermostat in - infact the b**ger who had it before had ripped this out - probably to try and cure this problem.

However, now I'm at a bit of a loss as to what to do next.

I'm thinking the next course of action should be to get the radiator out and flush it through.

Is there anything else I should be looking at?

many thanks
Ex

[Mr2Mike]

Do you have an oil pressure gauge as well? If the pressure is too high, from either a stuck relief valve or one that has been "modified", this can cause the oil to get hotter than normal.

[lx993]

The only time I've seen the oil temp gauge go above half way is on hot track days i.e. sustained full throttle. Even at Hethel a few weekends ago (i.e. 32 deg C) the oil temp never got that high. (and this was an 8000 rpm engine!!!)

Water temp's a different matter - but if you're getting the STOP light on for very high oil temp then I'd get the sensors checked first. You'd need some SERIOUS friction in the engine to overheat the oil in 15 minutes, is the motor producing the expected power??

Equally if there is no water in the system, the entire engine will overheat big style. I know that the water temp gauge may not read correctly if not covered in water (i.e. empty system), but the 205 has 2 water temp sensors (one for gauge, one for STOP light) so this shouldn't be an issue.

I'd check that you've got water circulating properly when it gets hot, then check the oil temp sensors. The 1.6 shouldn't be boiling its oil unless there's something seriously wrong.

[theexcession]

lx993 said:

The only time I've seen the oil temp gauge go above half way is on hot track days i.e. sustained full throttle. Even at Hethel a few weekends ago (i.e. 32 deg C) the oil temp never got that high. (and this was an 8000 rpm engine!!!) Water temp's a different matter - but if you're getting the STOP light on for very high oil temp then I'd get the sensors checked first. You'd need some SERIOUS friction in the engine to overheat the oil in 15 minutes, is the motor producing the expected power?? Equally if there is no water in the system, the entire engine will overheat big style. I know that the water temp gauge may not read correctly if not covered in water (i.e. empty system), but the 205 has 2 water temp sensors (one for gauge, one for STOP light) so this shouldn't be an issue. I'd check that you've got water circulating properly when it gets hot, then check the oil temp sensors. The 1.6 shouldn't be boiling its oil unless there's something seriously wrong.

The engine is totally standard and is as quick as it ever was so I'm thinking maybe this is a sensor failure that is getting worse.

Tonight on the way home the oil temp levelled it self just below vertical (with the stop light on) and the water temp got up to the second mark where it stayed for the entire journey (20 miles).

In traffic queues the oil temp got a bit past vertical - I aggree with you this is serious friction to generate so much heat - but the engine is pulling fine - just a bit rough at idle - hunts a bit sometimes - jeez at these temps you'd think it might seize or wonder how it could even run...

I've found the oil temp sender and tried pulling the lead off it and this causes the gauge to go to zero but the oil temp light (at then end of the gauge) still stays on so are there two oil temp sensors? - maybe I need to study the schematics....

This has me totally flumuxed... I guess tomorrow I'll try flushing the radiator.

So, how do I check the water is flowing properly? It is topped up and I've run the engine from cold with the expansion tank cap off - there is a steady stream of water running into the expansion tank from the narrow top hose - is this normal?

thanks
Ex

[theexcession]

Mr2Mike said:

Do you have an oil pressure gauge as well? If the pressure is too high, from either a stuck relief valve or one that has been "modified", this can cause the oil to get hotter than normal.

The oil pressure gauge is behaving as normal. The engine is totally standard.


thanks
Ex