1991 Honda Accord is running rough and the engine vibrates? (Japanese, plugs, fuel)

[tillman7]

Timing belt was changed in 2008.

[M3 Mitch]

Well that sucks. Since the head has to come off, the timing belt has to be at least de-tensioned, I'm not certain exactly how much else you have to take apart on this particular car - but since most if not all Hondas are interferance engines, I would spring for the additional parts for at least the belt itself, I would have the mechanic cast a baleful eye on the tension roller and the water pump, if they don't look essentially new, I'd replace them too.

I guess you know if you break a timing belt, *assuming* the pistons don't get beat up too bad, you will be doing the head gasket job over again but installing a rebuilt or ex-junkyard head.

[tillman7]

Originally Posted by M3 Mitch

The cheapest bid is not necessarily the best. But it may be. Make sure you are getting high-quality parts, and probably it's worth considering replacing all the exhaust valves anyway. Depends on what shape they are in. If you just had one tight valve and it burned, you may only need to replace that.

You should be getting a new timing belt and water pump as part of this. Will add to the cost now but save you going in to do them later.

I had the valve work done, now the car smokes when I start it in the morning after sitting idle overnight. It does not smoke when I drive the car. What could be the problem. Could it be oil leaking past the value guides?

[M3 Mitch]

That would be typical of bad valve guide seals. At this point I would say "grin and bear it" and see if "break-in" of the new parts makes this go away or not.

What work, exactly, did you have done?

[tillman7]

Originally Posted by M3 Mitch

That would be typical of bad valve guide seals. At this point I would say "grin and bear it" and see if "break-in" of the new parts makes this go away or not.

What work, exactly, did you have done?

^^they said they “removed and sent cylinder head to machine shop to have valve job. Replaced head gasket, intake gasket, thermostat and gasket, rocker shaft seals, tube seal, valve cover gasket and cam seal, changed oil and filter and power steering pump ring." The car drives and runs fine! But when I start it in the morning, a plum of light blue smoke exits the exhaust pipes. It stops smoking when I drive off. If I drive or let the car run for about five minutes @10:00pm at night, when I start the car in the morning, it does not smoke. If the car sits for about twelve hours, that's when it smokes in the morning.

[Gimme3steps]

Normally it's not a good idea to do a full valve job on an engine with 150000 miles on it. Doing a valve job will not only increase compression and put added pressure on the compression rings but it can increase engine vacuum and pull oil up past worn out oil rings. Sounds like that may be your problem.

On a high mileage engine, it's usually best to just do the bare minimum head work to get it back in service.

[gbugmiami]

Originally Posted by Gimme3steps

Normally it's not a good idea to do a valve job on an engine with 150000 miles on it. Doing a valve job will not only increase compression and put added pressure on the compression rings but it can increase engine vacuum and pull oil up past worn out oil rings. Sounds like that may be your problem.

On a high mileage engine, it's usually best to just do the bare minimum head work to get it back in service.

Funny. My buddy is a honda tech. THAT is his normal advise. Just do what it needs to keep it going. For this scenario it would have been resurface and replace gaskets and seals, and roll on. ANd yes if the timing belt is off, you would normally just put it new. The water pump should be fine. Normally at least at the dealer, for newer cars even, they dont push this type of repair on a car with that milage, they will just do a junkyard motor.

[tillman7]

The Honda dealership says the problem is valve guide seals and two of the valves needs to be adjusted.

[gbugmiami]

Yes valve guide seals can cause that. They should have been done when they did the valves. Its a pita job to change them all with the head on the car.

[M3 Mitch]

Originally Posted by tillman7

^^they said they “removed and sent cylinder head to machine shop to have valve job. Replaced head gasket, intake gasket, thermostat and gasket, rocker shaft seals, tube seal, valve cover gasket and cam seal, changed oil and filter and power steering pump ring." The car drives and runs fine! But when I start it in the morning, a plum of light blue smoke exits the exhaust pipes. It stops smoking when I drive off. If I drive or let the car run for about five minutes @10:00pm at night, when I start the car in the morning, it does not smoke. If the car sits for about twelve hours, that's when it smokes in the morning.

No new timing belt? Given that this is an interference engine (I think) I would have changed it, even if it's not badly worn.

Again, this may go away over a period of a few weeks.

Given the facts on the ground as you present them, I don't see any reason not to just drive the car and see what happens.

Who did the work, dealer or indy shop? Did you go with the lowest bid? Did they use Honda or other parts?

My Scirocco came to me with Brazilian valve guide seals, these didn't seat properly on the head, "rode up" on the valve stems so effectively I didn't have any valve stem seals. The car used say a quart per 1000 miles but didn't smoke. Since then the head was re-done 2X and both times got German valve stem seals, typically does not use even a quart in 5000 or more miles.

I have heard the advice against doing a valve job on a worn motor, and yeah if the rings are badly worn doing a valve job just concentrates the leakage with the old rings, but both the 'roc and the Toy got valve grinds or replacement heads at over 150K miles and both worked out fine, on both cars I inspected the cylinders and found no obvious wear, I didn't use a micrometer or anything but no ridge that I could feel with a fingernail, etc.