twin turbo overheating

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twin turbo overheating

Post by mikekostiuk » Tue Aug 01, 2017 4:07 pm

I recently bought a 1987 twin turbo and while driving it i notice that the car quickly overheats even in cool 60 degree weather. The previous owner said the car ran in the low 200's around 212 degrees or so. For me it is running around 230 for about 20 minutes then jumps up to 260 degrees. Not sure if this could be just a bad thermostat or if its a radiator issue. Any suggestions on where to start looking would be appreciated. Thanks!

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Re: twin turbo overheating

Post by BIGJOHN » Tue Aug 01, 2017 6:15 pm

Clean your radiator may be full of leaves and gunk!
That is where I would start!

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Re: twin turbo overheating

Post by puzzigully » Tue Aug 01, 2017 7:53 pm


Sounds similar to my overheating issues.

Turned out to be approx 2/3 of the radiator was blocked.

Replaced radiator with extra heavy duty one and now it almost runs too cool!

Keep in mind the original radiator for B2K was a heavy duty from factory.

You can get an aluminium radiator locally from Dewitts for a great price. I'd start there.

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Re: twin turbo overheating

Post by Callaway Chris » Wed Aug 02, 2017 10:15 am

Which thermostat does the car have? In water neck, or external?

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Re: twin turbo overheating

Post by avcwo » Fri Aug 11, 2017 9:02 am

I agree with the others, road scraps accumulation in radiator gaps is notorious in C4'S. The other option that works GREAT is distilled water with Royal Purple Ice additive. Water is naturally a better transmitter of heat then 50/50 coolant. The RPI will prevent corrosion. You will see a 15-20 degree drop at normal operating temps. CTTCs and C4'S in general are hot runners, so anything you can do to reduce the temps is healthy for the longevity of the vehicle.
1987 CTTC #9 of 184

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Re: twin turbo overheating

Post by mikekostiuk » Fri Aug 11, 2017 10:59 pm

Thanks for the feedback! I was able to get in there and check the radiator for debris and did not see any. I did replace a few missing screws in the lower bumper that seems to have elevated it so more air is directed up toward the radiator. I took it for a ride when it was hot out the other day and it ran better but still a bit hot, getting up to about 225 F.

How do I figure out if my thermostat is external or in water neck?

I will give the distilled water a try.

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Re: twin turbo overheating

Post by SurfnSun » Sat Aug 12, 2017 1:36 am

External thermostat looks like should be swapped for a tradition intake manifold mounted unit.

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