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.

"...Engine otherwise runs like a close..."


Like a clock I of course meant.

On 3/11/2013 11:54 AM, Doc wrote:
> 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.
>

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

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

On Mar 11, 12:54*pm, Doc > wrote:
> 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.

try a new sensor before anything else.

"Doc" > wrote in message
...
> 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.

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

On Mar 11, 5:33*pm, "uncle_vito" > wrote:

> 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.


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.

On Mar 13, 8:01*pm, Doc > wrote:

> Per a Sunpro gauge it shows about a needle width over 5 psi at hot
> idle @ 700rpm.


And about 55 psi at 3000 rpm.