Possible explanation for low oil pressure light after cam seal install

89 Toyota Cressida recently mentioned in here with bad cam seal. Going down the road and find that a temp fix with Permatex on the seal didn't hold, by 200 miles into a trip the engine is hemorrhaging oil. Low oil pressure light comes on at idle though the light wasn't on going down the road. Find I'm over close to 3 quarts low.

Fill with oil and keep refilling about every 25 - 50 miles. Keep this up for about 200 miles. As long as I maintain this constantly refilled state the oil sensor light doesn't come on even at idle.

Get to mechanic friend's house, replace cam seals. Oil leak problem solved. Spray the engine down with degreaser similar to Purple Stuff. Thoroughly hose down engine from various angles to get grease and degreaser off.

Now, when the engine gets to operating temp and running for a while, I'm getting a low oil pressure light under 1000 rpm. Engine otherwise runs like a close. Smooth, strong.

Wondering why the oil pressure light would suddenly start coming on at idle when at road temp when it didn't before the cam seal replacement and engine hose-down.

Mechanic friend says hosing down the engine could have gotten water into the pressure sender and change the resistance value of the internals. I'm incredulous about this since it looks to me like a sealed unit. He swears water can get in around where the metal lower portion is crimped around the plastic top portion....?

I'm working on locating a mechanical oil pressure gauge to fit this vehicle to check the pressure.

Opinions on the possible cause of sudden oil pressure light given the above scenario?

Thanks.

Reply to
Doc
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"...Engine otherwise runs like a close..."

Like a clock I of course meant.

Reply to
Doc

No idea about yours but engines with worn bearings/journals show that low pressure at idle symptom.

Reply to
AMuzi

try a new sensor before anything else.

Reply to
m6onz5a

I would use a mechanical gauge to be certain of your pressure. Perhaps you did some damage before your seal repair by running your engine when low on oil. That is what the light meant when it went on at low rpm before your seal fix.

You may have damaged some bearings during this leak escapade. Run thicker oil as a mitigation measure rather than rebuilding the engine, but do that only after measuring oil pressure with a mechanical gauge and fixing any indicated problem such as the pressure sensor.

Vito

Reply to
uncle_vito

Per a Sunpro gauge it shows about a needle width over 5 psi at hot idle @ 700rpm. So let's say 6 psi. Toyota factory manual says 4.3 is minimum. Replaced the sensor and the light doesn't go on any more. Will have to find time and motivation to pull the pan and pop off a bearing cap or two to see what it looks like.

Still wondering why the old sensor suddenly started giving a low reading only after an engine wash down. Could there be anything to the notion of water intrusion? I thought the units are sealed.

Reply to
Doc

And about 55 psi at 3000 rpm.

Reply to
Doc

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