89 smokes when you start/step on it.

[lab350]

Hi all,
New to the forum. I bought an 89 5.0 Mustang GT convertible, 70k from a 50yr old in May 09. The car has been babied and meticulously cared for. I noticed when I first bought it would smoke/blue alittle when first starting and when you step on it. It does not seem to be burning any oil etc. The car was not driven much/stored for about 5yrs. I drove it about 500 miles since May. I love the car, but am bummed at why it is doing this. Also, since the weather got colder it seems like it is doing it alittle more... Could any mods cause this? Cats have been removed and new exhaust installed. It has a Cervini true ram air hood installed Could a mod like this alter anything else that should have been changed when hood was put on? Also the factory plugs and wires are still intact. Could this cause it? It runs like a charm so I am trying to see what you guys think. Thanks for your help. M

 

[8850vert]

this could be two things. After a Car sits for a while it can build up a ridge in the cylinder wall. If this happens when you first start the car and it revs up the piston rings break through the ridge which in turn scratches your cylinder wall. This would cause oil to slip by the rings and burn. Another option is after a vehicle sits for a long period the valve seals can dry out. When this happens oil will seep by the seals and in to the combustion chamber. It will then burn and end up coming out your exhaust. These are two possibilities. I believe it is a valve seal issue. It is very common in ford 302 motors that sit for a while if not started regularly. I hope this helps. By the way congrats on your new toy. Pull the motor and build it. yeehaw.

 

[87GT40]

+1 on the valve seal issue.

 

[90mustangGT]

Definalty sounds like a valve seal issue. This is more of an age issue than wear issue. These can be replaced on the car, with the engine in tact, and isn't really that bad, just going to be dedious and time consuming because you have 16 of them.

While you have the upper intake off, you might want to take the fuel injectors off and get them cleaned.

 

[Repostyle]

Definalty sounds like a valve seal issue. This is more of an age issue than wear issue. These can be replaced on the car, with the engine in tact, and isn't really that bad, just going to be dedious and time consuming because you have 16 of them.

While you have the upper intake off, you might want to take the fuel injectors off and get them cleaned.

Yup, valve seals. But I would pull the motor and re-ring it also since it smokes after start up too. It's not that much more work to R&R the motor versus just the heads, and it's easier to work on a stand.

The injectors aren't causing any smoke issues, but it's a good idea since you'll be in there anyway and it's really not that expensive, around $10-15 each. It will help revive some of the cars fuel mileage and power.

 

[90mustangGT]

Yup, valve seals. But I would pull the motor and re-ring it also since it smokes after start up too. It's not that much more work to R&R the motor versus just the heads, and it's easier to work on a stand.

The injectors aren't causing any smoke issues, but it's a good idea since you'll be in there anyway and it's really not that expensive, around $10-15 each. It will help revive some of the cars fuel mileage and power.

True but valve seals can be done on the car without removing the heads.

When you talk about re-ringing the cylinders do you rehone them to, or if the crossthatch pattern is still good just put new rings on it and let it fly? Thinking of doing this to mine. 183K miles on it but it was very well cared for, good oil pressure, no smoke or blowby.

 

[Repostyle]

My motto has always been it's easier and better peace of mind to do a little more work now rather than a lot of work later. I would pull the heads and re-seat all the valves too. There's no reason not to re-hone the cyl's, as long as you have it apart why not? If they're good it won't take very long and if there not then it was all worth it to begin with. But the rings don't wear perfectly, so it will leave groves in the cyl walls as they wear together, it may not have any issues now, but putting a new round ring in an oval or whatever odd shape hole will cause problems later.

So as I said before, it's better to pull the motor and replace the rings too, replacing just the seals might be easier, but if it doesn't solve the smoke issue because of blow by from the rings, then you have to pull it all apart again. Plus when the motors out it gives you a chance to clean it up and make it look nice again. Do it once and be done with it.

 

[fox89]

i have an 89 mustang 5.0 it smokes when i get on it it smokes pretty bad! but when it idles it doesnt smoke, piston rings or valve seals? my motor does have gt40 heads a cam and crane cam rockers. any ideas?