rchalmers3
I speak Toyota
Hello all, I've been off this forum for awhile, having become addicted to playing with ex-military trucks (US 2.5t "deuce and a half" multi-fuel cargo trucks) for the past year or so. I am back on board with some questions regarding the motor in a Landcruiser a friend just bought.
The vehicle is a 1997 HDJ80 (HDJ80L-GCMEX for those of you who can read Toyota speak) with the 1HD-T turbo diesel inline six with the H151F 5 speed trans.
We bought the truck knowing the oil pressure read low on the factory gauge when the engine is at operating temp. BTW, indicated pressure is acceptable (and verified with a mechanical gauge to be good) with the engine cold.
When we got it home I checked the readings with a mechanical gauge on a warmed up motor and sure enough we are only getting 7 psi @ idle and 25psi @ 2000 rpm. I can realize 35psi by revving the motor to 2700 rpm. Specs for this engine are minimums of 4psi @ idle and 35psi @ 2000rpm. Oil level is full on level ground. Filter looks new and oil color is.... well it looks like diesel engine oil!
Questions:
* Does the 1HD-T have any known oil pressure regulator issues (wear causing the plunger to hang, or plunger springs that weaken) that may be at cause or contribute to low pressure once the engine is warm?
* Is it likely the Big End Bearings (BEB) problems known on this motor will account for most of the warm engine oil pressure loss or do the mains (or cam bearing surfaces) also wear and loosen up?
* Are there any other important ideas or issues inherent to this motor for me to consider? Oil viscosity characteristics for example....
First thought is to replace the unknown factor: the oil, to see what difference (if any) that makes.
My second thought is to perform a replacement of the BEB's in car to restore oil pressure. I performed a search and read on some older threads there may be issues with the rod cap bolts and am wondering if that is really an issue or if folks are playing it safe. Anyone experienced on that?
Thanks in advance for your knowledge and experience. For those of you who go gaga (can I say that anymore?) over Landcruisers with ambulance doors, I'll post some pics if you need your fix.
Ta,
Rick
The vehicle is a 1997 HDJ80 (HDJ80L-GCMEX for those of you who can read Toyota speak) with the 1HD-T turbo diesel inline six with the H151F 5 speed trans.
We bought the truck knowing the oil pressure read low on the factory gauge when the engine is at operating temp. BTW, indicated pressure is acceptable (and verified with a mechanical gauge to be good) with the engine cold.
When we got it home I checked the readings with a mechanical gauge on a warmed up motor and sure enough we are only getting 7 psi @ idle and 25psi @ 2000 rpm. I can realize 35psi by revving the motor to 2700 rpm. Specs for this engine are minimums of 4psi @ idle and 35psi @ 2000rpm. Oil level is full on level ground. Filter looks new and oil color is.... well it looks like diesel engine oil!
Questions:
* Does the 1HD-T have any known oil pressure regulator issues (wear causing the plunger to hang, or plunger springs that weaken) that may be at cause or contribute to low pressure once the engine is warm?
* Is it likely the Big End Bearings (BEB) problems known on this motor will account for most of the warm engine oil pressure loss or do the mains (or cam bearing surfaces) also wear and loosen up?
* Are there any other important ideas or issues inherent to this motor for me to consider? Oil viscosity characteristics for example....
First thought is to replace the unknown factor: the oil, to see what difference (if any) that makes.
My second thought is to perform a replacement of the BEB's in car to restore oil pressure. I performed a search and read on some older threads there may be issues with the rod cap bolts and am wondering if that is really an issue or if folks are playing it safe. Anyone experienced on that?
Thanks in advance for your knowledge and experience. For those of you who go gaga (can I say that anymore?) over Landcruisers with ambulance doors, I'll post some pics if you need your fix.
Ta,
Rick
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