Stuttering at Spa?

[DuncanR]

Originally Posted by shimmy

I love all our technical discussions ESP when NZ_M3 and The Gorilla are involved.

Trouble is I am not clever enough to understand who is right everytime

+46 of us !!!

[shimmy]

ignoring the fuel starvation on RHD crners at 1/4 tank fuel, i think the fuel system is the root cause of the high temps at 100% throttle on hot days that i and others have experienced. Even FLOW got a bit at ZOLDER.

could the fuel at 100% THROTTLE be running short and running the engine lean and therefore hotter thus affecting oil temps and eventually water temps?

[shane@mbtech]

Originally Posted by shimmy

ignoring the fuel starvation on RHD crners at 1/4 tank fuel, i think the fuel system is the root cause of the high temps at 100% throttle on hot days that i and others have experienced. Even FLOW got a bit at ZOLDER.

could the fuel at 100% THROTTLE be running short and running the engine lean and therefore hotter thus affecting oil temps and eventually water temps?

I had zero issues Shimmy and I stayed out for approx 10 laps on the trot at full throttle. My oil temp and coolant temps ran far lower than yours did. Yours has a new engine, which for me points to external cause.

I had the fuel starvation at 1/4 tank of fuel too.

Unless you need a new fuel pump I doubt it is that. Have you tried a new fuel pump or even a fuel filter?

Other possibilities....... radiator
oil cooler
sticking stat(oil too)
restriction in cooling system

[AlexGTT]

Originally Posted by lawsy

I had zero issues Shimmy and I stayed out for approx 10 laps on the trot at full throttle. My oil temp and coolant temps ran far lower than yours did. Yours has a new engine, which for me points to external cause.

I had the fuel starvation at 1/4 tank of fuel too.

Unless you need a new fuel pump I doubt it is that. Have you tried a new fuel pump or even a fuel filter?

Other possibilities....... radiator
oil cooler
sticking stat(oil too)
restriction in cooling system

Shane, I'm totally convinced the issue is radiator. I had a similar slight rising temps at a very hot Donny the other day. However, oil temps stayed beautifully under control. That didn't happen before the bigger oil cooler went in. The oil temps would rise with water temps with the standard oil cooler.

The issue is, I'm sure, old stuffed up water rads. Not just external blockages (flies and shite between the fins, etc.) but internal build up which reduces the efficiency of the rad. 99% of the time the heat generation is handled but on track with compounding heat build up @100% throttle on a hot day and the heat gradually overtakes the rads ability to extract the heat.

If it was a fuel issue the lambda's and knock sensors would be going nuts and the ecu would pull things back timing wise, etc. Hence why the engine stutters on genuine 1/4 tank and less with fuel starvation.

I'm changing the radiator for a new oem asap.

[shane@mbtech]

Originally Posted by AlexGTT

Shane, I'm totally convinced the issue is radiator. I had a similar slight rising temps at a very hot Donny the other day. However, oil temps stayed beautifully under control. That didn't happen before the bigger oil cooler went in. The oil temps would rise with water temps with the standard oil cooler.

The issue is, I'm sure, old stuffed up water rads. Not just external blockages (flies and shite between the fins, etc.) but internal build up which reduces the efficiency of the rad. 99% of the time the heat generation is handled but on track with compounding heat build up @100% throttle on a hot day and the heat gradually overtakes the rads ability to extract the heat.

If it was a fuel issue the lambda's and knock sensors would be going nuts and the ecu would pull things back timing wise, etc. Hence why the engine stutters on genuine 1/4 tank and less with fuel starvation.

I'm changing the radiator for a new oem asap.

Thats my thoughts too Alex, but I dont have the rising oil/coolant temps. I will wait until I do.

Forte do a great coolant degreaser type product, used it only today on a car which had a failed water seal dumping all oil into water, and vice versa. Works a treat, its worth a try before taking off rad, esp for people who have to pay to get rad changed.

[shimmy]

Do it Alex but I'm sure it won't help.

My money is on the fuel or ecu and I'm my heart everything is saying that the car is running lean at full throttle.

I'm pretty sure I can check this easily with my Rev App or maybe someone has a GT1 that I can plug in. Theory states that the pressure should not drop as you hit 100% throttle.

Here is a good item from dragsters

http://www.automotiveu.com/SolvingOverheating.htm

[shane@mbtech]

Originally Posted by shimmy

Do it Alex but I'm sure it won't help.

My money is on the fuel or ecu and I'm my heart everything is saying that the car is running lean at full throttle.

I'm pretty sure I can check this easily with my Rev App or maybe someone has a GT1 that I can plug in. Theory states that the pressure should not drop as you hit 100% throttle.

Here is a good item from dragsters

http://www.automotiveu.com/SolvingOverheating.htm

If it was running that lean that the car overheats, it would blow up in my opinion.

Have you ever changed fuel filter?.

[shimmy]

Originally Posted by lawsy

If it was running that lean that the car overheats, it would blow up in my opinion.

Have you ever changed fuel filter?.

Can't remember.

I think I might change fuel filter and regulator and I have a spare fuel pump to try as well.

How hard is it to swap out filter and regulator?

[AlexGTT]

Shim, you are correct and fuel mixture does have a significant effect on engine temps. However, when you look at the extremely high state of tune with the E46 motor, I would expect to see holed pistons and more extreme damage and not just raised temps. Believe me, I've seem less highly tuned motors grenade themselves after just a few seconds of unchecked lean running at 100% throttle at near max rpm.

[AlexGTT]

Ah ha, snap Shane!