Replaced starter, engine now overheating
05-13-2007, 02:08 PM
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Replaced starter, engine now overheating
Hi everyone. I'm quite new to this forum, as well as to DIY jobs on audis yet the amount of help I've received just by reading posts has been unbelievable. Hopefully, I will be able to return the favour soon enough. Now, onto this problem I'm encountering.
I just finished replacing the starter on my 1993 Audi 90 Q. Had to remove the drive belt and alternator to do this. However, the day after putting it all back together, engine overheats and antifreeze goes everywhere.
After a few days of testing I've noticed the following:
- doesn't overheat while idling, only after driving for about 10 minutes (then fans come on like jet engines).
- Water pump pully seems to be working fine
- opened up one of the bleeders and coolant came out, doesn't seem to have air in pipes
- Hose coming from block to rad top gets very hot
- Hose coming from rad to engine warms up eventually
- top of rad doesn't get hot except near the return hose from the engine.
- rad does not warm up throughout
The fact that the whole rad isn't warming up makes me think that the coolant is obviously not flowing. Am I correct to assume that this is either a faulty water pump or blockage in the rad?
I haven't flushed the rad yet as I wanted some 2nd opinions first.
I read that usually you'll hear the bearings starting to go in the water pump prior to it breaking down. I did not hear this.
As well, is there any correlation to perhaps low drivebelt tension and this problem?
I realize there are a lot of questions here but any input would be helpful. Thanks!
I just finished replacing the starter on my 1993 Audi 90 Q. Had to remove the drive belt and alternator to do this. However, the day after putting it all back together, engine overheats and antifreeze goes everywhere.
After a few days of testing I've noticed the following:
- doesn't overheat while idling, only after driving for about 10 minutes (then fans come on like jet engines).
- Water pump pully seems to be working fine
- opened up one of the bleeders and coolant came out, doesn't seem to have air in pipes
- Hose coming from block to rad top gets very hot
- Hose coming from rad to engine warms up eventually
- top of rad doesn't get hot except near the return hose from the engine.
- rad does not warm up throughout
The fact that the whole rad isn't warming up makes me think that the coolant is obviously not flowing. Am I correct to assume that this is either a faulty water pump or blockage in the rad?
I haven't flushed the rad yet as I wanted some 2nd opinions first.
I read that usually you'll hear the bearings starting to go in the water pump prior to it breaking down. I did not hear this.
As well, is there any correlation to perhaps low drivebelt tension and this problem?
I realize there are a lot of questions here but any input would be helpful. Thanks!
05-13-2007, 02:28 PM
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Re: Could be a bad thermostat too.
Thanks for your reply.
I was thinking that, however, from what I've read if the thermostat is fully closed your top rad hose will not be hot when the engine is - which isn't the situation. As well, the engine seems to warm up normally which would discount an always open thermostat.
Maybe it could be the t-stat not opening all the way, reducing the flow of coolant. Has anyone encountered that situation?
I was thinking that, however, from what I've read if the thermostat is fully closed your top rad hose will not be hot when the engine is - which isn't the situation. As well, the engine seems to warm up normally which would discount an always open thermostat.
Maybe it could be the t-stat not opening all the way, reducing the flow of coolant. Has anyone encountered that situation?
05-13-2007, 06:31 PM
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Re: Replaced starter, engine now overheating
don't know what you took apart to replace starter, but feel your hoses to see if both are getting hot. If one is hot, would suspect thermostat. If both are hot, would suspect waterpump. That is, if the coolant temp. sensor is reading accurately. But don't rule out fans, check to see if they are coming on.
05-13-2007, 06:39 PM
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Re: Replaced starter, engine now overheating
Both hoses become hot after not very long however the top rad hose (coming from the engine into the rad) gets hot quicker. The electric cooling fans really only come on when the engine begins to overheat. They normally rarely come on otherwise.
