Rebuild or buy used???

Alright, I can't figure out what's wrong with my car, neither can the shop, and neither can this board. I'm the guy that keeps blowing out valve cover gaskets after the head rebuild on my 199,000 mile 88 5spd TC. Just to catch you up, everything in the pcv system has been cleaned or replaced. Vacuum is good, compression is 150 across the cylinders. Car runs absolutely excellent and is very very strong. But...about every two weeks the valve cover gasket blows out for no apparent reason. Remember me now?? Anyway, I've decided to either rebuild the engine or buy a used engine and drop it in. I'm asking your advice on which method would be better. Like I said, the car has 199,000 miles but it has a completely new top end. (Well, the head was a 100,000 mile piece that was gone through and resurfaced, new cam, lifters, followers, and all that.) Is that mileage too much to think about a rebuild? Or should I find something with less miles? Cost is a factor, so throw some ideas my way and let me know what you think. Thanks
Kev

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Kev
88 TC 5spd Black body, red leather, K&N in front of the radiator, bypassed BCS at around 17 psi, polished throttle body, 2 1/2" dynomax ultraflow mandrel bent duals. 255 lph fuel pump, totally rebuilt head with Melling cam kit

To rehash this a bit, if the PCV system is clean and has no problems(this especially includes the vent from the valve cover to the turbo inlet), then likely it has worn rings that loose their seat with boost. In this case the ones I have seen, usually blow oil out the dipstick as well, do you have this problem??

It's getting hard to find good used engines these days, I'd consider a rebuild if its a keeper.

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Three 1988 Turbo Coupes .....
yea one of em has a 5.0 And runs 13.1s......
uhhh make that [email protected] with a 90hp shot of nitrous.

Nope, no oil out of the dipstick. Everything is perfect that can be checked, but it still blows out the valve cover gasket. After the first three times of blowing out the valve cover gasket, I decided to try something new. So I plugged the rubber hose going to the turbo inlet, and left the breather open to the air. My thought was that any kind of air building up in the valve cover would escape through the breather this way without any kind of pressure holding it back. I ran with it like this for about 2 weeks and no oil ever came out of the breather outlet, but at the end of the two weeks, it was the same situation. I was just pleasantly driving home and I smelled oil. I looked behind me and there was the cloud. I drove the 5 miles home smoking like I was a James Bond reject. I popped the hood and the valve cover gasket had blown out again but not a drop of oil had escaped the breather element. I can take the breather element out of the car and blow through it easily. I just don't understand what it could be. The gasket I put on was the expensive blue rubber one with the inserts for the bolts. My question I guess is What type of parts do I need for a bottom end rebuild, and how can I tell if my bottom end is in good enough shape to handle it? Bore it over? What size pistons, where do I get the parts? I don't really know about the inside of the engine and these engines last a pretty good while so there really isn't a lot of info on this sort of thing in this site. Anyone who has done this sort of thing, I would like to hear from you to get an idea of the trouble and cost. Please help, I'm looking into buying a 300zx if I can't get this done. Yeah, I know that's more money to buy another car, but I can do that through the bank and pay for it for 5 years. Thanks again.
Kev

I had a "good" rubber gasket and it blew out fairly quickly. I now use a cork gasket and have no leaks and no problems. I even had this one off 3-4 times and it is still fine. Just my $.02.

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88TC
current mods: ported & polished big valve head(1.89/1.59), ranger roller, custom upper and ported lower intakes, t3/t4 turbo, powerstroke intercooler mounted full size, 60mm throttle body, R.C. Engineering 42lb. injectors, MSD 6al, MSD Launch Control, MSD 8.5mm wires, K&N filter, Walboro 255HP pump, Kirban adj. fuel reg., ATR header, full 3" exhaust with Dynomax Ultraflow muffler, Star stage III clutch, Hallman boost controller, Flex-a-lite adj. temp switch for stock fans, Weld Draglites with M/T ET Street 26x11.5/15

Coming very soon(ordered and on the way) SDS, 73pph injectors, custom roller cam

I had the same problem.your not overtighting them are you?even with the metal rings i think the can be over tightened. i took my valve cover to work and put it on a granite plate (which is flat within .0001 ITS really flat lol) i must say it was not even close to being square(FLAT) so i sanded on a flat plate and kept checking till it was.It worked for me.I bet my cover on the back passenger was a good 1/8 inch or more higher than the rest. mine was blowing out the front drivers side which means tighten the back front will raise more than the rest

Originally posted by Glenn 88TC:
I had a "good" rubber gasket and it blew out fairly quickly. I now use a cork gasket and have no leaks and no problems. I even had this one off 3-4 times and it is still fine. Just my $.02.

Hummm Glenn sounds like your .02 might save someone a bunch of money.


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Three 1988 Turbo Coupes .....
yea one of em has a 5.0 And runs 13.1s......
uhhh make that [email protected] with a 90hp shot of nitrous.

You may be thinking too much about this problem. Did you change the valve cove itself. It may be worped or bent and the gasket may only be able to hold out so long.

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88 TC X 2 One stock one not so stock.

I agree, I think the flange on your VC may be the problem...

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Dan Eaves
88TC 5spd, Crower 5.5" Sportsman Rods, Short Wiseco Pistons bored .030" Over, Ported Head with Polished Combustion Chambers, Gutted & Polished Upper, Ported & Polished Lower, Polished T/B, Ported E6, SVO T3 .63AR Turbo, Bosch Bypass Valve, 3" DP w/No Cat, 2 1/2" DynoMax single cat back w/DynoMax Super Turbo Muffler, RR Cam, K&N in Fenderwell, Gillis Boost Valve, Centerforce I Clutch, Removed A/C, Polished Wheels, Polished Valve Cover, Polished Crank and W/P Pulleys, Walbro 255LPH HP Pump, Kirban Adj FPR, and the DAMN Heater Core is new too !

NATO MEMBER (Vice Chairman...if it's a vice...I deal with it)

That is a good idea to check the flatness of the valve cover, and the head surface for that matter. But, I'm using the same valve cover that I used for the first 198,000 miles of the engines life, would it being on a different head cause the unevenness and the blowing out valve cover, you think? Something else to check, I guess. But I can rip and tear on the engine revving it high and keeping boost at 17psi for long periods of time, and the valve cover always blows out on one of those slow, boring drives to the grocery store. What do you think is up with that? There is a mustang guy about 25 miles west of me, maybe I'll go see if he has any engines that he'd like to sell. He may have some turbo stuff for me, thanks again for all the help.
Kev

Kev, You had this valve cover on another engine, right? If so you may have bumped wrong or did maybe something fall on it or did it get dropped?

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88 TC X 2 One stock one not so stock.