Overheating!
06-08-2005, 02:57 PM
#1
Drifting
Thread Starter
Overheating! (fixed it was water pump)
Just when I get everything finished and ready to drive this happens. A little history first. I purchased car a year ago it sat for 4. I changed all hoses, belts, wires, total tune up. Runs great i put 1500 miles on it in a years time. It has alway ran at the first mark on the temp gauge.
I was driving home from a family function and looked down at temp gauge and noticed it was getting hot, so I got on the highway thing cold air would help. The wind on radiator did not help it kept rising. I wipped it into a driveway and opened hood, no leaking no steam look good. I let it set for a while and took off cap and th water level was fine. I it cool and drove it home the whole way it kept rising it rose to the three quarter mark and stayed the whole time. The temp stayed on the 3 mark untill i hit the driveway and it jumped to the last notch and spewed out a lot of coolant. The next day I bought a new thermostat and installed it and flushed coolant. Started it up and it does the same thing it takes about 9mins to got to first mark then about 15-20 to three quarter mark and then it will gradually overheat. I see no water in oil and no oil in water. It is not loosing water either. Water pump maybe?? both sides of radiator is hot and hoses are hot and have pressure. Im sick to my stomach thinking about this. Any help would be appreciated.
I was driving home from a family function and looked down at temp gauge and noticed it was getting hot, so I got on the highway thing cold air would help. The wind on radiator did not help it kept rising. I wipped it into a driveway and opened hood, no leaking no steam look good. I let it set for a while and took off cap and th water level was fine. I it cool and drove it home the whole way it kept rising it rose to the three quarter mark and stayed the whole time. The temp stayed on the 3 mark untill i hit the driveway and it jumped to the last notch and spewed out a lot of coolant. The next day I bought a new thermostat and installed it and flushed coolant. Started it up and it does the same thing it takes about 9mins to got to first mark then about 15-20 to three quarter mark and then it will gradually overheat. I see no water in oil and no oil in water. It is not loosing water either. Water pump maybe?? both sides of radiator is hot and hoses are hot and have pressure. Im sick to my stomach thinking about this. Any help would be appreciated.
Last edited by icsmike; 03-29-2006 at 07:46 PM. Reason: fixed
06-08-2005, 03:09 PM
#5
Drifting
Join Date: Jul 2002
Location: Los Angeles, CA
Posts: 3,348
Likes: 0
Received 0 Likes
on
0 Posts
Sounds like when my water pump started to fail...
The pump has a plastic impeller, and when the splines strip, the belt will still
turn, and the pump will still turn, and it won't leak, but it also won't be pumping
any water. It makes sense that the pump might be bad, because it will still
semi-spin some of the time, and may work for a while, then start spinning
completely when the water heats up. Since you already replaced the thermostat,
you could try checking for blockages. Test the radiator, and make sure
something has not collapsed or blocked flow. If your radiator tests out
ok, then it's time to tear into the water pump...
The pump has a plastic impeller, and when the splines strip, the belt will still
turn, and the pump will still turn, and it won't leak, but it also won't be pumping
any water. It makes sense that the pump might be bad, because it will still
semi-spin some of the time, and may work for a while, then start spinning
completely when the water heats up. Since you already replaced the thermostat,
you could try checking for blockages. Test the radiator, and make sure
something has not collapsed or blocked flow. If your radiator tests out
ok, then it's time to tear into the water pump...
06-08-2005, 03:47 PM
#6
Addict
Rennlist Member
Rennlist
Site Sponsor
Rennlist Member
Rennlist
Site Sponsor
Be sure that the rubber thermostat O-ring is the correct thickness and installed in front of the thermostat (toward the radiator). Often the generic replacement thermostat is supplied with a Mercedes O-ring seal which is too thin to push the thermostat all the way back into the housing. This allows water to continue to recirculate in the engine and not go through the radiator.
Trending Topics
06-08-2005, 07:14 PM
#9
Rennlist Member
Also, if your car is a S4 with the variable control cooling flap nightmare in front of the rad - it may have failed in the most likely position ..... closed, therby starving the rad of fresh air.
06-09-2005, 01:42 PM
#10
Drifting
Thread Starter
Thanks for gettin back so soon. The car is 86.5. The previous owner did the TB and doesnt? know if they did WP (wow). There is no blockage and I did get all air pockets out. The electric wasnt working but thanks to a quick call to Dave Roberts I solved that one. Even with the electric fan same thing. One thing that is odd I noticed after it got extremely hot, everytime I blip or rev throttle when I let of there is now a "pop" in the exhaust.
06-09-2005, 02:23 PM
#11
Rennlist Member
Are you running too lean?
06-10-2005, 03:05 AM
#13
Rennlist Member
Either gone lean, or timing retarded will lift temp. retarded timing will produce more heat as you go faster, BTDT. Lean mix would have to be very bad to change temp seriously - power should be noticeably down. Both are very bad for the insides.
jp 83 Euro S AT 49k
jp 83 Euro S AT 49k
06-10-2005, 04:18 PM
#14
Drifting
Thread Starter
Well I think the problem surely showed itself today. Only one side of radiator is hot now the other side cool to touch. I disconnected hoses and ran water with garden hose through it and it flows great. Im betting on water pump.
