Oil Pressure & Temp

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jimmyboy
Posts: 2
Joined: Sat Aug 16, 2008 6:53 am

Oil Pressure & Temp

Post by jimmyboy »

Hi,

Just installed VDO Pressure and Temp gauges and they scare me. Pressure starts out at 60lbs and drops off to 5 or 6 when the temp gauge reaches 230-250 F. Should either of these conditions exist. Putting an analog thermometer on the temp sender where it goes through the case reads 190F.

Another glitch is the engine seems to miss or "choke" at arbitrary times. can't find a pattern to it. New filter. Any sensors to replace?

Oh, 81, camper, 2Ltr. FI, GEX rebuilt installed in 95. No idea how many miles cause odometer was broken.

Advice??
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raygreenwood
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Joined: Wed Jan 22, 2003 12:01 am

Post by raygreenwood »

If its an oil pressure gauge that uses a small bore hose full of oil...is off.
Where are you taking the pressure from, what type of sender unit is it.

Also...if its a GEX.....I would tear it down and inspect it before its too late. Ray
Pillow
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Joined: Mon Oct 15, 2001 1:01 am

Post by Pillow »

Also where are you taking the oil temp numbers from?

Anything over 210 and you should be worried... Normally, but it depends where the sender is.

Mine will run 230 tops but the sender is in the oil filter housing which reads higher than a normal sump install.
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raygreenwood
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Joined: Wed Jan 22, 2003 12:01 am

Post by raygreenwood »

Pillow, thats intersting to hear tha. Just wondering if you can speculate as to why the sender reads higher in that position.
Not to get off topic, but in a conversation with Piledriver a little while ago regarding oil temps in his cabriolet...we both nocticed the same thing. Our oil temps tended to run to about 110-120C all day everyday at highway speeds. :shock: ...with no apparent ill running.
Then again...they are taken right at the oil filter neck. I always knew teh temps were not that high...that it had to be something about the location of the sender. Ray
Pillow
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Joined: Mon Oct 15, 2001 1:01 am

Post by Pillow »

Ray, I cannot explain it myself with good reasoning.

In the Speed & Drag Racing forum some respectable people weighed in and said that the remote oil filter locating is the best place to monitor oil temps. For some reason it is the most sensitive to temp changes and also reads higher than the standard sender locations.

The only theory I have is that the oil is circulated so fast in the engine that a case mounted sensor does not have time to "heat soak" for an accurate temp. The remote sensor is catching the oil in its flow stream and since so much volume is being pumped through the system it is a true reading as it does not have time to puddle and cool off.

Hopefully that made some sense. :)

In my case the sender change was an increase of 20F. But for me on a hot day I can push it to 230F which is like 210 on a standard setup. About there you will notice a little drop in oil pressure as well, which tells me to back off a little on the go juice. Interesting to note that the head temps never change, they are like a rock the whole time. Engine RPM and ambient temps are what heat the oil up for me. Then again I run a 2007cc T1, with the old 1600 I had it would run 190F all day no matter what you did to it (even cruising at 4200!).
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