Hydrolocked?
Hydrolocked?
How would you know if you hydrolocked the engine by turning it over after a leaky injector filled the cylinder head up over night...or worse yet....you changed an injector and let the fuel rail empty into the cylinder. Would the car still start? Would you be burning white smoke? Any dead giveaways?
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: Hydrolocked? (Locknut)
Hydrolocking normally bends the rods/rod and that cylinder loses compression. Consult power balance test should be a clue, then measure compression.
We have a wall of shame where the bent rods, wrist pins, and pistons are hung to remind techs to be careful when injectors are involved.
We have a wall of shame where the bent rods, wrist pins, and pistons are hung to remind techs to be careful when injectors are involved.
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goody90q45
- Posts: 3679
- Joined: Wed Aug 17, 2005 2:07 pm
- Car: 1992 Infiniti Q45 (sold)
- Location: Orangevale, CA
Re: Hydrolocked? (Locknut)
I've owned my Q for 18 months and have 2 episodes of exactly what you are describing. It's scary when you try to start the car and all you hear is a loud clunk. Both times my hydrolocking was caused by the lower o-ring slipping off one FI (#1 then #8) and flooding all four cylinders in the bank.
I think your next step is to determine which bank has the leak. Unless you have a Consult available you're probably going to have to pull at least one plug on each side and look for wet plugs. If you're lucky it will be the PS bank that's flooded where you've got a 50/50 chance of it being the leaky injectors (#2 or #8) that you don't need to remove the plenum to get to.
For now, pull the fuse on the fuel pump and let the cylinders drain. You will probably see fuel in your oil and will need to change it and the filter when you get this all sorted out. The second time this happened I had so much fuel in my PS bank that it was coming out the cat.
By the way, both injectors that I pulled were missing the pintle cap. I think they help to keep the o-ring in place when it's seated in the fuel rail. Let us know what you find. Good luck
I think your next step is to determine which bank has the leak. Unless you have a Consult available you're probably going to have to pull at least one plug on each side and look for wet plugs. If you're lucky it will be the PS bank that's flooded where you've got a 50/50 chance of it being the leaky injectors (#2 or #8) that you don't need to remove the plenum to get to.
For now, pull the fuse on the fuel pump and let the cylinders drain. You will probably see fuel in your oil and will need to change it and the filter when you get this all sorted out. The second time this happened I had so much fuel in my PS bank that it was coming out the cat.
By the way, both injectors that I pulled were missing the pintle cap. I think they help to keep the o-ring in place when it's seated in the fuel rail. Let us know what you find. Good luck
Re: Hydrolocked? (goody94q45)
Thanks guys...I'm going to pull some plugs to take a look. The injector I replaced a few months ago just had upper and lower o rings. I didn't see any pintal "caps" just the rubber/plastic coating on the tip. Anyways....the car just gradually started to turn over longer and longer on startup after sitting over night...like it had lost fuel pressure. It never really knocked hard when I started it...so it's hard to believe i could have bent any rods without a good thump. The white smoke is puzzling though...shouldn't it be black if I was flooding a cylinder? Can you blow a head gasket when you hydrolock? Maybe now I'm leaking oil into a cylinder. I heard synthentic oil burns white not blue. Anyways...thanks for your thoughts.