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Topic: Vaccum problems Very strange (Read 1146 times) previous topic - next topic

Vaccum problems Very strange

Maybe you guys can give me some insight. I have a rebuilt head with custom power heads cam and rebuilt shortblock. I only have 6* of vaccum at idle at 1100rpm and car blows oil out of dipstick and valve cover at 5-13psi of boost.

I have tons of vaccum, like my wifes hoover vaccum hose, from the dipstick tube at idle. Also if I pull off the oil cap slowly it sounds like a hoover vaccum there too. Is this normal? Is this a sign of big valves not seating,  maybe my new rings, or just plain old pcv? I replaced the whole pcv system back to stock as suggested by the other boards and still it blows lots of oil at boost out the dipstick (no longer from valve cover because I have hose routed back to the turbo snout). Need ideas. I'm stuck big time.
Motorsport FMIC, Boport 1.5, Boblee header, gutted upper, profiled lower, phenolic spacer, Accufab fpr, LA3, Boport stage 3 big valve head, 57 trim/stage III Perfromance Techniques custom turbo, stinger 3" DP and custom 3"exhaust, AEM wideband, custom aluminum carnk pulley, Merkur custom A/C setup, PA performance high output 3G alt, dual oil catcj cans, Motorsport Valve cover,full Motorcraft tune up kit, 22psi of LOCO!!

Vaccum problems Very strange

Reply #1 –
it sounds like your rings are toast

first, do the basics, do a compression and leakdown test, check your PCV, see if air passes through it, that stuff
It's Gumby's fault.

Vaccum problems Very strange

Reply #2 –
Quote from: Tbird232ci
it sounds like your rings are toast

first, do the basics, do a compression and leakdown test, check your PCV, see if air passes through it, that stuff


I agree, especially with the leakdown test... Sounds like the rings are not seated causing siginificant blowby... Leaking rings or a hole in a piston, is just about all that can cause the kind of crankcase pressure you are describing...