Have a 300GD short from 1983, with the STT Turbo kit. Well ... Over 3800 rpm with A/C the engine temp goes up to 110oC and stays there. Without A/C it goes up to 105oC. In traffic is 90oC. That is in Cyprus were the temperature is currently around 30oC.
Fitted larger radiator, replaced visco fan, water pump, and still the problem remains.
check termostat ! it has to open by 80° C so put is in some hot water and watch , it's p...
check termostat ! it has to open by 80° C so put is in some hot water and watch , it's possible that it would open but not far enough ! in that case you cane remove it for some days and drive around , if its mutch better you have to order a new one !
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MB 1982 300 GD
3 inch of lift
body-lift
winch
33x12.5-15 Goodyear MT/R
Check the thermostat first. It is the most likely problem. If not then pull the water pump and check the clearances.
Not all water pumps are made with the correct vanes. Also your water pump housing may have corroded such that the clearance is too great. If either is the case your pump will not move enough water to keep things cool.
Hi Alan
I'm running a bit hot still after replacing the rad. and themostat. My next move was going to be the waterpump ,thinking that it might have worn to such an extent that it wasn't moving the water.
Whats tests can you suggest for checking the pump insitu?.What life could you expect from a MB pump? .I thought that the seals would go before the impellors would wear. Mine is constantly running at 100 C now even in the cold.But then the thermostat doesn't fully open 'till 95c anyway so maybe all is OK.
Aside from end play and leak testing, I can't think of any direct (external) measure for water pump function. If you have been using non-mb coolant the housing may have corroded away due to chemical etching or cavitation. That happened to my 230SL. Seperating the housing I found that the housing was worn back 3mm or so. The pump was spinning away but having little effect due to the clearance.
Using the MB coolant is strongly recommended by the MB oldtimer mailing lists. In the US is is actually made by Zerex. Just recently the MB formulation has become available as G-05 (I think that's the Zerex name for it).
Something else to try & a pointer for quieter running
Thank you all for the information. The MB service station here has checked the housing and water pump.
One thing I'll try today, is to remove the bonnet to see whether the problem might be caused by insufficient ventilation of the engine bay. I've been told by a G guru in Germany to cut holes on the sides of the engine bay, and put vents on the front side panels, to create ventilation.
U see, the car is RHD, and the turbo, manifold, brake booster, A/C compressor are on the right hand side of the car. Things are a bit packed in there.
For all those of u having a W460, one way to reduce the vibrations and noise from the drivetrain is to use spacers to lower the transfer case so that the angle of the driveshafts is reduced.
Thank you all for the information. The MB service station here has checked the housing and water pump.
One thing I'll try today, is to remove the bonnet to see whether the problem might be caused by insufficient ventilation of the engine bay. I've been told by a G guru in Germany to cut holes on the sides of the engine bay, and put vents on the front side panels, to create ventilation.
A trick from the tipsters at Geländewagen und Freizeit magazine is to remove the rubber gaskets that run along the engine cowl and mate up to the back edge of the engine hood. This will allow more air flow through the engine compartment.
A friend of mine runs this conversion in the Uk (not as hot here)but RHD, in a LWB and he has raised his bonnet slightly to improve cooling.
This was done with the adjustable stops on the leading edge of the bonnet - he also modifed the hinges so the gap all around is slightly larger - but is even.
The STT conversion moves the air intake from inside the engine bay to the front lip of the bonnet, using a metal fabricated extension. In order for this extension to take-in air, STT provides a kit for raising the bonnet for just a few cm. I have it installed.
The conversion is great, pushing power to 129bhp and torque to around 240Nm.
Linear Mode
