*MAP - A reading of 6-8 at idle is good. It would measure about 18-22 in-hg of vacuum. MAP stands for Manifold Absolute Pressure. So pressure is low (vacuum available at idle) and decreases under acceleration.

*Blowby - Blowby should be assessed w/ PCV hooked up. If PCV is blocked or plugged, you will get blowby for sure. All engines have some blowby. That's what PCV extracts from a good engine. In a worn engine, blowby exceeds ability of PCV to extract. See following video:

PCV - check that PCV valve "rattles" and you can blow through in one direction and not in other. Check that hoses are clear and stiff enough not to collapse when suction is applied. A collapsed hose would prevent any PCV activity.

Oil Pan - Suggest using appropriate gasket from Felpro to seal. Only use hondabond at the valley edges on one end. I might use a 3-4 small spots of hondabond to stick the gasket to the pan w/ a few bolts installed to insure gasket is aligned and does not move when installed.

good luck

 

Sounds good -- thanks for the confirmation.

When I pull the PCV and hold the tip of my finger up to the opening at the bottom of the PCV, it sucks fiercely. I replaced it last year with a Honda OEM one (For $25 ... ugh) But the orifice is so small, it is definitely getting overpowered by the amount of positve air flow coming out of the oil filler hole when I pull the cap off.

Yes, I'm pretty sure the PCV is working correctly. I wish I could make it suck out more air

I bought a Honda OEM gasket and some HondaBond. I will take your advice of putting on the mininal amount of HondaBond, and see how it goes. Worst case I'll have to pull the pan again and apply more bond.

--- Latest thoughts ---

So there is a lot of air coming out of the crankcase through the oil filler opening. If the compression check is good then that means I don't have leaky rings or valves ... then the only thing left is worn and leaky valve guides and/or a blocked exhaust.

The other symptom I would like to point out is that the engine revs seem to run out os steam around 4k ... I can push it above 5k if I really step on the gas, but it seems like there is some resistance in the engine ... something that excessive exhaust backpressure you think would cause.

What are you thoughts on that?

Thanks. John

 

Before replacing the oil pan gasket, you need to get to the bottom of excess blowby. Suggest performing a leak-down test to confirm whether valves or rings are the source of blowby.

I've never heard of valves causing excess blowby so suggest more testing since 4 oil pan gaskets have failed (pretty good evidence of excess crankcase pressure!).

You can purchase a leak-down tester for < $30 (ebay, amazon, etc) or make your own. See videos on youtube by richpin06a on making and using leak-down tester.

good luck

 

My compression test this morning was 165-165-165-165 ... I don't think the rings or valve seats are worn with that good a compression, no?

I'm not the one going on 4 oil pan gaskets ... this is the first time I've done this after purchasing the car 3 years ago with 228k miles on it. Someone did pull the pan before, though, since there is a gasket on there. It could have been on there for 100k miles. I should also note that when I got the car and started working on it, I discovered one of the pan bolts was missing, yes missing, and I soon discovered it was being used with a fender waasher to hold up the splash shield. So the pan torque was probable not right for quite a while.

Fyi, while you were writing your response, I was pulling the pan The pan practically fell off the car, and lots of oil around the entire gasket area, and rtv residue buildup here and there on the mating surface of the block. So I'm guessing whoever did this last time did a terrible job. So I'm in it for the first time today, and I'll have to look at the pressure issue afterwards. Worst case I'll have to replace the gasket again in the future, but again as I said the pan seemed pretty loosely attached, and the gasket felt hard with age, so I'm hoping with a new gasket I'll have better results.

Fyi the inside of the engine is a golden amber ... go Penzoil!

*** update ***

I ran out of time today, so the pan is loosely bolted onto the engine for now, and exhaust manifold/pipe plugged with rags ... the car will have to sit for a couple of days until I have the time to finish it. Hopefully by then we'll have more ideas on what is the cause of the crankcase pressure.

 

Finished the oil pan gasket yesterday morning. I actually spent around five hours more on it after the initial three -- most of that time cleaning parts of oil reside (from the prior leaks) and dealing with the gasket removal.

Removing the gasket from the pan was a royal pain! I took someone's suggestion of putting a heat gun on the gasket so it would "peel right off" ... not! That gasket material could coat the bottom of the shuttle as far as I'm concerned. It still took a lot of patience and muscle with a chisel to get the gasket off ... over an hour on this.

Then, there was still a lot of gasket material "baked" onto the pan. I tried scraping with a razor blade for 10-15 minutes, but after realizing that was a futile effort, I took out my drill and wire brush and ground the rest of it off, taking the paint off the lip in the process (as well as some of the skin off my hand) and bringing it down to the bare metal. At least the surface was squeaky clean at this point ... but what a pain.

I would guess this was original on the car. As far as people's claims that Honda pans did not have gaskets from the factory ... this pan has nubs that separate it from the engine block by maybe a millimeter, and the gasket has holes in it that correspond to the nubs, to help keep the gasket in place as it's tightened down. So I think there is a factory gasket on these.

The Honda OEM gasket is a soft squishy rubber and it squished down pretty well as I torqued the bolts, oozing out all around the pan. I was very careful to torque in small increments, and took around a half hour to tighten the bolts in several stages. At one point I thought I would never reach 10 ft-lbs ... the bolts just kept turning. I was afraid I would strip the threads in the block. But eventually I got there.

Fyi for good measure I pulled the oil strainer to check if it was clean (it was) and put a new gasket on that as well.

considering how loose the pan was before, how hard and brittle the old gasket was, and how much I've squished this new gasket in place, I'm guessing this isn't going to leak anymore, crankcase pressure or no pressure.