2001 Winstar - Valve Job?

I have a 2001 Ford Winstar that has started developing problems and I have no idea what to do. The check Engine light is on with Lean Codes (I dont have the Numbers). About a week ago while driving the engine kind of choked up and lost all power. I thought that I heard a pop and then the engine took off again. But under less power. The engine was running very rough. The exhaust was very stinky. I took the van to a local certified mechanic and got it back yesterday. He changed the spark plugs and says that one of the cylinders is dropping out. During compression check he said it registered 70 PSI and then a second check registered 90 PSI. He stated that I need a valve job. He said it was an exhaust valve because he put a rag over the exhaust pipe and it sucked back into the pipe a little. He also said that it is possible that carbon buildup on the exhaust valve may burn away and it might run fine. The problem that keeps coming to mind with me is that this was not a gradual loss of power. This happened at one moment. Can a valve go bad that quickly? Also what are the ramifications of driving it to try and "Clean it out"? Can I cause more damage to the engine. The van runs better since he changed the plugs but it still runs rough at low RPM and lacks power at low RPM. I have filled up the tank and put some Gumout Fuel System cleaner in the tank to try and help the "CleanOut" situation. How can I be sure that I need a valve job? I would hate to burn that kind of money for work not needed. It already set me back $200 for the plugs and diagnostic.

Can A valve go bad that quickly?

Should I get a second opinion?

What are the ramifications of driving with a bad valve? To "Clean it out"?

What about the Catalytic Converter, I have head that with a missing cylinder it may be possible to damage the converter?

Thanks In Advance

Hello,

I hope I can answer some of your questions.

Welcome to AFs!


1. Can A valve go bad that quickly?

I don't think a valve can go bad that quickly. I would pull the valve cover and check for a broken valve spring on the exhaust valve. Did he tell you which cylinder? Did he show you the spark plugs?

2. Should I get a second opinion? I would give the cleaner a chance for a bit.

3. What are the ramifications of driving with a bad valve? To "Clean it out"? I don't think it will hurt it. I wouldn't drive it real hard or for an extended time.

4. What about the Catalytic Converter, I have head that with a missing cylinder it may be possible to damage the converter?

I think the computer can turn off the injector to the cylinder that's missing.



How many miles do you have on your 2001? How long have you owned it?

Regards

Dan

I thinking you got a 171 -174 which would be the upper intake isolator bolt issue. If it is bad than you can run into a problems with loss of power and with a vac leak coming from the problem can cause problems along the way if left unchecked. How long was your check engine light on before you went to have it checked.? When this repair is done the upper intake gaskets along with the isolator bolts should be changed. Also the EgR ports should be cleaned. Now here is the other problem. If the problem had been around for a while and excess carbon built up on the valves a hot spot can form on the valve or valves. If this happens the valve or valves can become brittle and erode away. Now to me if you went with the CEL light on for a year or more I could see this happening. It takes time for this to get real bad. So you may want to look into it more. Like other post a valve spring may have gave out. There is a lot of factors that come into play with out knowing the problem first hand. But keep your hopes up for something simple.

I agree with checking on the upper intake bolts ... also all hoses in the area, could be just a sudden broken hose.

I may be the only person around this forum fearful of "cleaners". I once wiped out a cat convertor on an otherwise good car just doing what I thought was good preventative maintenance ... adding a good dose of Chevron Techtron injector cleaner to the tank.

I'd get the second opinion and a third. I'd get an opinion from a Ford dealer too, if the diagnosis charge isn't too much.

In my opinion, accurate diagnosis of a valve problem requires a series of measurements, including compression and vacuum measurements, as well as checking out other less intrusive causes of the symptoms.

However, an experience mechanic would be able to use their insight to shortcut the process.

I don't see how leaking intake gaskets can cause low compression (70 psi is pretty low). Did he take 'wet' readings as well as 'dry' readings? Is that why there were two numbers (70/90)? If the rings are bad, then the wet readings will be much higher than the dry. I think the 20 psi difference you're seeing is well within what you'd expect, indicating a valve issue.

If you decide to go in the direction of the valve, I agree that the valve springs should be checked before pulling the head. Valve springs do fail suddenly. Also, a spring can fail without breaking clear through. There was a post here a few months ago from someone who had a failed valve spring. A valve spring can be replaced without removing the head.