My oil pan gasket keeps leaking on my built ls/vtec. I see it leaks more on the timing belt side for some reason. It like to leak more when its in vtec because I can see after drives when I using vtec a lot (track days) there is oil on the LCA, axle, back of the brake caliper, subframe.

I've changed the gasket 4 times already and the last time I changed it I put a different oil pan on because I thought maybe the last one was warped. But it is still doing it. I've used OEM Honda gaskets and Felpro (I've had no problems with the Felpro leaking in the past). I've tried using a little Ultra Grey and a lot of it with still the same issue. Both surfaces are clean and as dry as I can get them. The last time I changed it (1 month ago), I put a different pan on, Felpro gasket, and Ultra Black sealant on the pan and the top of the gasket. Tightened it down to tq specs and left it there to dry for 24hrs before I put oil back in the motor and started it up.

Being that I notice it leaks more under VTEC (pressure) it is making me thing that maybe I have too much crankcase pressure. It is a B18a1 block with the breather box on the back going to my intake manifold using the PCV valve inbetween (ITR head).

My oil pressure gauge at idle reads 25psi. In VTEC, my oil pressure gets up to 87psi (autometer gauge and its inbetween 75 & 100psi).

Is this too much pressure and would it cause the oil pan gasket to leak? It is the ONLY problem I have ever had with this motor. It runs amazing.

What can I do and what are my options? Any ideas?

 

You don't need to silicone the whole gasket, just the corners. That's what the gasket is there for...did you replace the oil pump? Did you silicone where the oil pump mates to the block? Use hondabond next time too....

 

I've tried just putting silicone on the corners and none at all with still the same outcome. Brand new OEM Honda ITR oil pump and yes I put silicone where it mates to the block.

I always used ultra grey and used it when I assembled the block and haven't had any problems using it before.

 

The shop manual does recommend using RTV sealant on the gasket. Make sure to apply sealant to the inside edge of the bolt holes and be certain that the mating surfaces on the block, oil pan and both sides of the gasket are absolutely clean beforehand. Scrape off any old sealant and clean a couple times with rubbing alcohol. You may also want to clean the block all around just above the oil pan so if oil is dripping down from somewhere, you'll be able to tell that it's not from the oil pan.

 

the rest of the block is clean. There is only oil residue from the oil pan gasket down. It's not dripping or anything. It's being "sprayed" out that's what it getting all over everything that is in the driver wheel area.

That's why I am thinking I have too much crankcase pressure under VTEC causing it to blow out.

 

You can try removing the PCV valve, sticking a hose in the hole and blowing into it while the oil pan is off to make sure there isn't a blockage. Did you replace the oil pump o-ring and, if so, what did you replace it with? I once replaced it with a generic o-ring. The o-ring melted and the pump was spraying oil all around the front of the motor (timing belt side). I really think you should take a closer look at the oil pump. Have a new genuine Honda o-ring ready when the pump is removed. Oil pressure at idle when the motor is hot should be about 10psi and it should be around 50psi at 3k rpm. Higher pressure points to a blockage somewhere in the oil system. With proper crankcase ventilation, no amount of oil pressure will create a leak at the oil pan because the pan is just a resevoir that shouldn't be under pressure. A leak at the oil pump can be difficult to see because the timing cover is in the way.

 

I used a new OEM Honda ITR oil pump along with all new OEM honda parts when I built the motor.

I'm wondering if my black breather box on the back of the motor is block up? it was used.

 

The black boxes do have a tendency to get full of nasty black crud. Big clumps of it.

 

Try blowing air through it.

 

I'll have to take it off and check it.

My oil pressure at idle (800rpms) is 25psi. At 3000 rpms it's at 75psi.

The oil pressure gauge is located on my oil line going from my block to my head supplying the oil for the ls/vtec. It is about 4 inches along the line off the block. Could the size of the oil line increase the pressure?

 

Yep. Pushing fluid past a restriction increases pressure and decreases flow. The bigger the oil line is when used with a given sized pump, the less pressure the oil will be under and vise versa. The more torque the pump is using to push the oil, the less a restriction will affect its overall flow. It's the same way the FPR and master cylinders work- like holding a finger on the end of a water hose to make it spray further.

 

What shop manual recommends using RTV on the oil pan gasket? My 94 Integra Helm's makes no mention of using ANY sealant whatsoever on the oil pan gasket. As such, I used none on mine, and I've had zero oil leaks around my oil pan for over a year, and zero oil leaks on the entire engine period since last Thanksgiving (replaced oil cooler o-ring that was leaking).

I actually thought my oil pan gasket was leaking, but after replacing the oil cooler o-ring, that completely fixed the problem.

 

I might try it again with no sealant, but I've used silicone before with great sucess. The first one I ever did on my B18c1 almost a year and a half ago is still not leaking and that was using a felpro and ultra grey.

 

Honda civic (96-00), CRV (97-01) and Integra (94-00) Haynes repair manual page 2B-15.

 

Did you check to see if the block mating surface is level? I had the same problem with mine and noticed that where it leaked there were some little dents on the block mating surface probable from something hitting it. I gave it a gentle file and filed the dents with gasket silicone and voila, the leak was gone.

 

i am having this exact same problem with my ls/vtec setup it never used to do it but for some reason it started leaking one day so i changed it and didnt use any sealant.. it still leaked so i pulled it off and cleaned it up again and tryed it with some ultra grey.. still leaked.. so then i bought another new gasket and tryed mega grey and spent about 45 mins cleaning the surface of the block and the pan.. still leaking!!! im begining to think that maybe my black box or pcv valve is messed up and its building too much pressure cause i drove my car with this ls/vtec for over 3 years with no leaks and now i cant get it to stop

 

I am sure you are suffering from excessive crankcase pressures as you have suspected...
Running an external/ additional can with bigger hoses should help tremendously...
I had the same problem on my engine, added an external catch can, and my stubborn oil pan gasket leak went away like magic!
Might be in my mind, but the engine seemed to run better too. "freer" so to speak.

 

It's probably your oil pump seal...

 

btw i am wanting to do the catch can setup where u take off the black box and plug the whole and then take out the huge allen head plugs on each side of the oil filter and get the fitting to fit the holes and run them too a catch can but i have a obd0 b18 block and it has a sensor in one of those plugs... anyone know if i need that sensor?

 

FOR THOSE WHO ARE LEAKING ON THE TIMING BELT SID EI CHANGED A MILLION GASKETS EVERY WHICH WAY TO FIND OUT ITS THE OIL PUMP/CRANKSHAFT SEAL ....

 

same problem here. b20 vtec.oem honda gasketed the crap out of the sump and the block and fitted a new gasket, tightened form middle bolts to outside so not to crush the gasket and the bloody thing still keeps popping out with the bolts torqued to 8lb/ft (or was it nm)

popped out twice so far. not its decided to pop out right over the tri-y and i had oil burning off on the mani in traffic (was pretty funny!)

so fed up now. never had a problem before. block looks level with no dents/dings and weather i put the bolts on looser or tighter it makes sfa difference to it sealing. crankcase pressure should be ok as i am running 3 head ports and one large rear block to free air 1 liter catch can!