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MODVP22
10-23-2003, 07:52 PM
I have a 350 H.O. create engine that I bought new from GM Performace last fall (not a remanufactured). I put it in my truck, a 1986 GMC 3/4 ton 4x4. After 174,000 miles, the old one was tired out, so I bought this motor, got a Edlebrock intake for it, Edlebrock 600cfm carb and used the electronics from a stock GM 350. Runs great..when it runs right. This thing has blown the intake manifild gaskets out of the ends twice, had issues keeping it warmed up, oils leaks, and my headers still leak (big suprise). Lastnight, a good friend of mine, who's a mechanic helped me swap out the intake gaskets again, and it sealed it up nicely. When I started it today, it idles right with no vacuum leak finally. But, I had white smoke coming from the tail pipes..when it warmed up it was still white exhaust, but not as much..what the heck is wrong with this thing? I also noticed a faint bit of oil in the coolant that I drained from the block when we swaped intake gaskets. No water int he oil, no drips other than oil on the floor.

Capt.Insane-o
10-24-2003, 03:23 PM
Pump it up to 15 pounds, let it sit overnight. Pull all the spark plugs out, pull the power to the coil and have someone turn it over and see if any antifreeze squirts out the spark plug holes.

heath brinkley
10-24-2003, 04:15 PM
was it a long block or a complete motor. I assume it was a long block since you used your own intake and carb. that would explain the leaks. good thing is , when you figure out where the white smoke is coming from, it's under warrenty.;) :) :)

MTCM
10-24-2003, 04:54 PM
Sounds like Head Gasket(s). Pull the heads and have a look..........................it will tell you something one way or the other. Good Luck

MODVP22
10-24-2003, 07:17 PM
The motor is 2 months out of warrenty :(
I'm going to do a leak down test tomorow with my BALT leakdown tester from Balzy. A mechanic friend of mine told me that it sounds like I just spilled coolant into the exhaust ports and its burning off. The oil I found in the pan of drained coolant was likely fromt he oil all over the motor where the coolant was drained from..he said. I am running out of time and $ being the middle of the school semester...cross ya fingers for me guys that it's not a head gasket.

NPW
10-24-2003, 08:15 PM
Sounds like maybe the PCV system either not hooked up/plumbed wrong/no vent..This will let her build pressure inside crankcase,causing oil leaks and blown seals/gaskets..where's the oil leaking from?Milled heads will also cause the mating surface at the intake ends to be to tight/squeezing out the rubbers..throw those seals that came with the gaskets away and use GM sealer in their place/about $10 a tube/will never leak there again..

just my .02

rev.ronnie
10-27-2003, 03:57 AM
Being in the engine building business for almost 20 years, we, among the industry have come to refer to crate engines as "core engines". The machine work is terrible, at best. Take the thing completely apart, line hone it, square the decks with a BHJ fixture, hone it with a torque plate ( if it isn't already too loose) or bore it .020 and index the bores correctly and get a nice coated hyperutectic piston set, resize the conn. rods with ARP bolts and balance the whole assembly. Then remachine the valve seats to where they should be, not hangin' off the face of the valve, and resurface the nasty twisted up heads. Then have the crank ground .010/.010 and use std. undersize bearings instead of the selectively fit GM stuff. Then put the whole thing together and enjoy it. Anything else is a patch job, and the thing will never be reliable enough for you to have any peace of mind with while driving. GM really sells real butchered up engines, for a lot of money. I remember the old LS-7's...the pistons would hit the crank, right out of the box. We never actally ran one without doing the above prep to them though. I rebuild a lot of "crate engines". I guess I should be thanking GM??:)