Hey all,
I recently found an oil leak on the front of my 1GR-FE, and it initially looked like it was the power steering pump. I rebuilt the power steering pump with new seals and it all looked good for a couple of days, and then the leak returned.
After doing a bit of research, I discovered that the leak I had was a relatively common occurrence on the 1GR-FE. It occurs enough that Toyota issued a service bulletin in the USA for vehicles with 1GR-FE motors; T-SB-0326-08 for Tacomas, EG049-07 for 4Runners, EG050-07 for FJ Cruisers, and EG052-07 for Tundras. Vehicle years covered are 04-08.
These leaks have been showing up for a few years now. Mine has occurred after 147,000km.
This leak occurs at the intersection point of the base of the head, the block and the timing cover plate on the driver side, and as such it is not easy to diagnose where the oil is leaking from if you didn’t know about the service bulletins.
This is what the leak looks like close to the intersection point;
If you leave it and don’t degrease the area, the entire drivers side of the block and underneath the oil pan can get covered in oil.
The fix for this leak is unfortunately a big job, and the timing cover must be removed and resealed. This means stripping down the inlet manifold and pulling off all accessories on the front of the motor. Repair times quoted in the various TSB quote 6.8-12.8 hours, but I have seen from various forums that actual repair times run well out past 20 hours of labour. Repair bills up to $3000.
Fortunately this is a job that the DIY mechanic can definitely do at home, and save a bunch of bucks!
Here are a few photos of my repair job;
Manifold off, electrical harnesses pulled out of way, inlet taped up. Radiator, fan and serpentine belt removed.
Rocker covers off, oil filter and thermostat housing removed, idler pulleys and crankshaft pulley removed, alternator removed.
Timing cover removed. There’s no need to disconnect the power steering lines or air conditioner lines, I just pulled both pumps out of the way slightly.
Here you can see where the oil leak has occurred at the intersection of the head and block. The silicon bead on the inside was not continuous across this gap, and you can see why in the photos below.
Timing cover with water pump removed. I replaced the water pump with a new OEM unit, as I could see both a coolant leak and an oil leak on two different bolts.
There are numerous different diameter and length bolts in the cover and the water pump. This is a good trick I learnt from a forum to keep track of all the bolts.
From here it’s just a matter of cleaning down the mating surfaces very carefully. I used a razor blade and a bit of fine wet and dry.
In this photo you can see why this leak occurs. Just above the bolt hole above the water gallery hole, you can see a long depression in the casting of the mating surface. It’s almost 1mm deep. There is also another slightly less deep depression above the next bolt hole up.
I suspect Toyota have fixed these casting errors from 2008 models onward.
On the way to being back together!
In the Toyota manual, it says to drop the oil pan to remove the timing cover. This requires dropping the front diff and power steering assembly. There’s no need to do this, and I left the oil pan on, and just dropped the 4 front bolts which go into the timing cover.
The only thing to be careful of is making sure the o-ring for the oil pump (which sits in-between the pan and timing cover) goes correctly into place when you slide the timing cover back on. If this o-ring is out of place, no oil pressure! It can be tricky getting the cover over the crankshaft, and I did a few dry practice runs before I put on the silicon. I also doubled up the silicon bead where the 2 depressions in the timing cover mating surface are. Unlike the rest of the cover which is metal-metal, these depressed areas require a good build up of silicon to seal properly.
Since my rebuild, I’ve done 100km and everything is bone dry still!
Good luck to anyone who does this at home!
Best
Mark
I recently found an oil leak on the front of my 1GR-FE, and it initially looked like it was the power steering pump. I rebuilt the power steering pump with new seals and it all looked good for a couple of days, and then the leak returned.
After doing a bit of research, I discovered that the leak I had was a relatively common occurrence on the 1GR-FE. It occurs enough that Toyota issued a service bulletin in the USA for vehicles with 1GR-FE motors; T-SB-0326-08 for Tacomas, EG049-07 for 4Runners, EG050-07 for FJ Cruisers, and EG052-07 for Tundras. Vehicle years covered are 04-08.
These leaks have been showing up for a few years now. Mine has occurred after 147,000km.
This leak occurs at the intersection point of the base of the head, the block and the timing cover plate on the driver side, and as such it is not easy to diagnose where the oil is leaking from if you didn’t know about the service bulletins.
This is what the leak looks like close to the intersection point;
If you leave it and don’t degrease the area, the entire drivers side of the block and underneath the oil pan can get covered in oil.
The fix for this leak is unfortunately a big job, and the timing cover must be removed and resealed. This means stripping down the inlet manifold and pulling off all accessories on the front of the motor. Repair times quoted in the various TSB quote 6.8-12.8 hours, but I have seen from various forums that actual repair times run well out past 20 hours of labour. Repair bills up to $3000.
Fortunately this is a job that the DIY mechanic can definitely do at home, and save a bunch of bucks!
Here are a few photos of my repair job;
Manifold off, electrical harnesses pulled out of way, inlet taped up. Radiator, fan and serpentine belt removed.
Rocker covers off, oil filter and thermostat housing removed, idler pulleys and crankshaft pulley removed, alternator removed.
Timing cover removed. There’s no need to disconnect the power steering lines or air conditioner lines, I just pulled both pumps out of the way slightly.
Here you can see where the oil leak has occurred at the intersection of the head and block. The silicon bead on the inside was not continuous across this gap, and you can see why in the photos below.
Timing cover with water pump removed. I replaced the water pump with a new OEM unit, as I could see both a coolant leak and an oil leak on two different bolts.
There are numerous different diameter and length bolts in the cover and the water pump. This is a good trick I learnt from a forum to keep track of all the bolts.
From here it’s just a matter of cleaning down the mating surfaces very carefully. I used a razor blade and a bit of fine wet and dry.
In this photo you can see why this leak occurs. Just above the bolt hole above the water gallery hole, you can see a long depression in the casting of the mating surface. It’s almost 1mm deep. There is also another slightly less deep depression above the next bolt hole up.
I suspect Toyota have fixed these casting errors from 2008 models onward.
On the way to being back together!
In the Toyota manual, it says to drop the oil pan to remove the timing cover. This requires dropping the front diff and power steering assembly. There’s no need to do this, and I left the oil pan on, and just dropped the 4 front bolts which go into the timing cover.
The only thing to be careful of is making sure the o-ring for the oil pump (which sits in-between the pan and timing cover) goes correctly into place when you slide the timing cover back on. If this o-ring is out of place, no oil pressure! It can be tricky getting the cover over the crankshaft, and I did a few dry practice runs before I put on the silicon. I also doubled up the silicon bead where the 2 depressions in the timing cover mating surface are. Unlike the rest of the cover which is metal-metal, these depressed areas require a good build up of silicon to seal properly.
Since my rebuild, I’ve done 100km and everything is bone dry still!
Good luck to anyone who does this at home!
Best
Mark
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