Isuzu SUV Forum banner
1 - 4 of 4 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
First off.... new to the boards. but have been a trooper owner since 1993.
I have an January of 87 trooper II. 2.3 four banger. It is one of the carbed type.The motor has been completley rebuilt. has about 4000 miles on it so far.
I am having an issue of where my check oil light keeps coming on. does not happen till After the engine warms up. Also if the RPM's get close to 1500 the light flickers a lil bit.... but if it goes below 1500 the light comes on and stays on till I get back up to speed. This happens mainly when I stop and the clutch is in and I am idling, but when I hit the gas to go again.... the light goes off.
The oil level is fine and full.
After reading the boards for a few days I saw that changing the oil might help this problem. So I just got through doing that a lil while ago.
I let the trooper idle after everything was done with the oil change.... just to see what it would do.... well after it warmed up.... the light came on.
BUT when you rev the motor to over 1500 RPM's the light goes out.
The original oil gauge has not worked in a couple weeks now. The part on the sending unit that connects the wire broke about 2 weeks ago while changing the fuel pump, SO I do not have a gauge to check pressure with at this time. BUT I have a set of AUTO GAGE gauges on there way to me right now and should be here by the weekend. These new gauges are the mechanical type and should give me a BETTER understanding of EXACTLY what kind of pressure I do have and what the pressure is when the oil light comes on.
Questions:
If the new guage says I have the needed pressure and the light still comes on...... is this the oil light sending unit telling me that it needs to be replaced?
Can the oil pump be going bad? Not sure if a new oil pump was installed with this new rebuilt motor or not. paperwork has been missplaced somewhere.

After the new gauges are installed (oil,water) , this weekend sometime, I will post the gauge pressure in a follow up to this so maybe someone can give me a few ideas on what the heck is going on.

thanks for all your time and the great boards.

Wes in NC
 

·
Registered
Joined
·
49 Posts
If the new guage says I have the needed pressure and the light still comes on...... is this the oil light sending unit telling me that it needs to be replaced?
Technically, yes. But with a mechanical guage, the idiot light really becomes MOOT.

Can the oil pump be going bad? Not sure if a new oil pump was installed with this new rebuilt motor or not. paperwork has been missplaced somewhere.
Usually, when an engine rebuild is done, the pump is measured for tolerance, and if in spec, then it gets put back on, otherwise it's replaced.

Now, it could be the pump pushing low pressure (gears worn), a clogged gallery, a plugged inlet screen etc.

*edit* To elaborate: When the oil is cold and the pump is worn, the oil is thick enough to be pushed through the worn pump. When it warms up, it thins out, and the pump can't push the oil properly. When you hit it up with RPM's, the pump pushes more oil through faster, reaching a satisfactory pressure until you take your foot off the gas /*edit

I'd be easy on the vehicle until you get the mechanical guage. That should tell you if things are in order.

I've seen in the past where if the pump is not primed properly with the engine rebuild, it can air lock. I've also seen shotty machine shop work where the block is not cleaned properly, and metal filings from the boring/honing process stay in the engine, and eventually get stuck in the screen.

Good luck!

Steve
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #3 ·
Still working on the mechanical gauge. BUT did manage to get the old gauge(one that came with trooper) hooked back up.
Old gauge says I have about 15 pounds of pressure when things get hotand you are idiling. and the idiot light comes on.
Is this a good pressure?
Ya think the idoit light sending unit may be bad???????
When first started the pressure is about 55 to 60 and about 30 going down the road. and about 15 when idiling at about 1200 RPM's.

ANY IDEAS ON THIS? Appreciate any thoughts you may have on the matter.

Will post new results when the NEW mechanical gauge is completly installed and set up.

Wes in NC
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #4 ·
Took a 30 mile trip to Advance Auto. Went to get some copper tubing to use for the new mechanical oil pressure gauge, instead of this nylon/plastic stuff. well close to have way home from Advance auto.... the guage dropped to almost zero. This is with the OLD original electric gauge.
Hoping the gauges are wrong and it is not the oil pump.

IF IT IS THE OIL PUMP.
What am I looking forward too.
engine pull?
or can it be done from the bottom?

Wes in NC
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top