88 orangepeel notch

Hello, new to this forum and also new to owning a mustang. I bought a 88 notch over a year ago with supposedly a rebuilt engine. I have no proof of the rebuild but it came from a friend of a friend and I do believe them. Motor is very clean and it did have new gaskets everywhere. From what I was told they ran synthetic oil in it during break in, but I also know from experience that they did not baby this engine. I drove the car for maybe 300/400 miles and it ran great but had a little oil smoke during hard acceleration, along with some black (car was never rechipped after rebuild- many aftermarket parts). So I thought I would change oil to mineral based oil and let the rings set in. Ran all summer, maybe 1000 miles or so and now its getting alot worse. It maybe uses 1 quart every 500-600 miles. Are my rings junk? Or should I throw synthetic back in and drive it. I went and got it dyno'ed and it put down 270 hp, 304 trq at the wheels. Dragstrip #'s are 13.50 at 109. Again , I really like this car, its just getting embarrasing. Thanks for any replys.

lxman1

It could be something simple like the intake gaskets are leaking and sucking oil in from the bottom of the ports or the rings could be bad or it wasn't machined properly. Might try pulling the intake and checking the gaskets for signs of oil being sucked in.

Oh and welcome to the forum.

TrimDrip

I would go to a thicker oil. Like a 20w-50 or a straight 50w.

It wouldn't hurt to run a compression test.

Have the track times been effected?

88 orangepeel notch

Thanks for the replys, I'll check both those suggestions when I get the car out of winter storage. I don't know if the track times changed, I only took the car to the track once to see what it does before I start tinkering. It needs a chip burned for it badly, its a real eye-burner when idling. Dyno guy says it would be $350-500 for custom chip. Does that seem like a fair price?

TrimDrip

I had a intake gasket that didn't seal on one port and it blew smoke out of it at idle. Not all the time though. Being under load makes me think that it could be blow-by. Try the compression test and post up some results.

I have seen a car not get the oil changed within 2 or 300 miles after the build until the oil light came on. After time it became a solid running engine that didn't use oil. If the engine is a high compression engine like 12:5:1, I could see where the rings would give up after a season.

Running the engine extremely rich like that is washing the oil off the cylinders and causing it to wear prematurely. You need to get that fixed soon.

88 orangepeel notch

Hey thanks, I never thought about gas washing the cyl. walls down. Great point. As for compression, I dont think he went that radical on it, it runs great on punp gas.

88 orangepeel notch

Oh, what kind of psi should I be looking for when checking compression? Sorry, my brain is still in snowmobile season up here, I'm still thinking 2-stroke motors.

TrimDrip

I am not for certain which range it is honestly. Also, it wouldn't hurt to do a leak-down test.

88 orangepeel notch

Sorry for changing the subject alittle, but if my car is running so rich, wouldn't you think mpg would suck? My wife and I went on a weekend trip last year and I got close to 28 mpg. I checked my speedo with my gps and its off 2 mph at 70. So I know 28 was pretty accurate. This is with the aode with stall , shift kit and 355 gears. I still cant believe it. Why would it only run rich at idle? I had a 160' thermostat in it but read that I need at least a 180' so I switched that, no difference.