'88 300SEL - high engine speed on hot start-up
12-01-2014, 12:09 AM
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1988 Mercedes 300SEL, 1991 Lexus LS400, 1972 Chevrolet Kingswood Estate, 1973 Pontiac Grand Ville
'88 300SEL - high engine speed on hot start-up
Hey guys,
We have owned our '88 300SEL (M103 engine) for many years (it was my car for a number of years and now it is my moms car) and have really had no trouble out of it, so we have been very pleased with it. However recently something is going on that needs to be addressed pretty quickly.
On "hot start-up" the engine RPMS will race very high, then go back down. It seems to be getting worse and more often. I had to drive the car today to pick up some parts for one of my other cars and had to make two stops. When I got back in the car and started it, the RPMS went to around 3000 rpms then shot back down to normal. I had to make another stop and got in and it initially raced to 4000 RPMS! People were looking like I was crazy and trying to blow the engine. Other than this, the car runs fine and very smoothly. No changes in that aspect.
I have no idea what is going on, but any information would be greatly appreciated.
Thanks!
We have owned our '88 300SEL (M103 engine) for many years (it was my car for a number of years and now it is my moms car) and have really had no trouble out of it, so we have been very pleased with it. However recently something is going on that needs to be addressed pretty quickly.
On "hot start-up" the engine RPMS will race very high, then go back down. It seems to be getting worse and more often. I had to drive the car today to pick up some parts for one of my other cars and had to make two stops. When I got back in the car and started it, the RPMS went to around 3000 rpms then shot back down to normal. I had to make another stop and got in and it initially raced to 4000 RPMS! People were looking like I was crazy and trying to blow the engine. Other than this, the car runs fine and very smoothly. No changes in that aspect.
I have no idea what is going on, but any information would be greatly appreciated.
Thanks!
12-02-2014, 11:56 PM
#2
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Join Date: Nov 2003
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1988 Mercedes 300SEL, 1991 Lexus LS400, 1972 Chevrolet Kingswood Estate, 1973 Pontiac Grand Ville
Hello?
Someone on another MB site said to check the OVP relay. That is on my list to check. Anything else?
Thanks.
Someone on another MB site said to check the OVP relay. That is on my list to check. Anything else?
Thanks.
