Hello everyone, I have a 99' E250, 5.4L with 75,000 miles on it, the #1 cyl. intake valve was stretched and caused it to (tulip) and misfire. Has anyone seen this and what would cause it? A bad fuel injector to cause a lean condition and get hot? I have never seen this before, any info. would be appreciated!

 

Is this something you have personally observed and measured, or was this related to you by a "mechanic"?

Pop

 

I've seen and heard of them but not on a 5.4 and not at 75K miles. I've seen it on 5.0's, some older 4.6's, and a few bikes. The cars had more than 100K on them and the bikes just weren't adjusted when they were supposed to be. A low quality steel used for the valve, hardened seats with a lot of high rpm's, and power adders can all cause it. I would ask to see the valve itself and the valve seat in the head.

 

I am a tech and personally removed the head and seen the valve, we send heads to a machine shop and thats what THEY call it, but its my first one I've seen.
Greg

 

This is a carpet cleaning van and the pump is (PTO'D) off the engine, so it runs from morning to night when fired up, more hours on the engine than the van itself.

 

That's probably why then. Would recommend a full set of valves (maybe an upgraded set with springs) if they aren't already planned for.

 

Tulip'd tips I've seen. Stretched stems I haven't.

Was the stem diameter significantly reduced as a result?

Pop

 

No, the stem looked ok, the head of the valve was more (of a bowl) as you would say.

 

You mean it got hot and flowed into a "cup" shape?

Are the rest flat?

Pop

 

Yes the rest were flat, the machine shop told me that they have seen them on the chevy's more before and it was usually caused by an injector and the combustion was lean and causing higher temps.

 

Did the stem tip need to be ground, due to the "tuliping", to get it out of the guide?

Pop

 

I have seen it on a few trucks at the dealership most where drivin for some time while skipping or hauling heavy loads while skipping most are commercial vehicles and mileage does not matter. I would stress test the coils probably had a coil go bad and they kept running it. The coils can breakup and not feel like a skip but still be skipping. The ford ids scanner can diag easier than an after market scanner.

 

It has had 5 coils go bad and that was one of them, who knows how long it went before the coil was replaced.

 

That valve had the most carbon build up on it also compared to the other three on that head.

 

I was a Chev tech for 8 years and I saw this a lot on all of their motors. I saw it on intakes and exhaust. I just chalked it up to crap valves. Mostly late '80s early '90s vintage. It looks just like it sounds, kind of like an inside out umbrella only not as extreme. I don't think a bad coil would cause it. The carbon was most likely from the misfire in that cylinder due to the lack of compression.