Problems with my 200

[mr_falcon]

I recently bought a 68 falcon with a 200 i6 and the engine doesn't run right. first thing i noticed was it was misfiring and smoking a lot, so i pulled my plugs and saw that most of em are soaked in oil. so i clean up the plugs, put em back and it runs fine for a while(cant remember if it was smoking at that point or not). but after about 10 mins it starts acting up again. so i pulled the valve cover and find a bunch of little plastic looking things just layin there, took me a little while but i finally figure out that its my valve seals actually crumbling. now i obviously have to replace my seals and plugs but can that alone explain all the smoke, it smokes all the time, basically as long as the engine is running theres lots of smoking coming out of the exhaust. do you guys think it might be a combination of seals and something else, rings perhaps, or replacing the seals alone can fix this issue

 

[addo]

The valve stem seals won't be your only source of oil smoke on a well-worn 200, but they can contribute a fair amount. Wear in the valve guide itself, will also allow more oil to be drawn in on the induction stroke.

Compression testing the motor (when fully hot) will allow some evaluation of the state of wear inside. Make sure all plugs are removed and the throttle plate held open when conducting the test.

Your final non-invasive test is the manifold vacuum at hot idle - check it's within specified range with a simple vacuum gauge.

Regards, Adam.

 

[rbohm]

8) in addition to what addo wrote, worn or gummed up rings will also allow oil to pass into the combustion chamber and cause smoking and plug fouling.

 

[mr_falcon]

so i'll definitely be doing a compression test to find out how bad my rings are but what does a manifold vacuum test tell me? and how do i know if my valve guides are worn?

 

[ludwig]

Tells you if the engine is even producing enough vacuum at all. Should be a minimum of 18*.

 

['68falconohio]

Ahh, I may be a little biased....but '68 is a good year.

 

[69.5Mav]

Do you know the history of this engine? How many mile, any recent rebuild, did it sit for a prolonged period?

Whats your plan for this engine. Do you want it to just run or run without smoking?

How much smoking will your local alow.

In the 70s I had a 235 I6 chevy that burned a quart of oil every 50 miles. The plugs never fowled at all, I was using fire injectors from JC Witney.

If you want to just get it to run then I would replace all the Valve seal including the exhaust valves, Install a set of fire injectors and change the oil now and often.

While your doing the compression test after you take all the reading go back and put a teaspoon of oil in each cylinder and retest the compression in that cylinder. This combined with the "dry" reading can give an indication of where the problem lies.

If this is a high mileage engine and given the regulatory atmosphere in this country your probly going to have to rebuild it soon.

 

[mr_falcon]

as far as i know there are 83k miles on the car, not sure of any rebuilds, and it sat for at least 2-3 years in a garage. basically what i want from this engine is for it to run well or at least decently and not smoke as much as it does now. i got the seals in today so i'll try to get them installed tomorrow and do a compression test to see where i stand. i'll check in once i finish up to tell you guys how things went