Just had a call from the dealer, my son's truck has two cylinders with no compression, I think he said 4 and 6. Not clear if it is low compression or no compression. Truck was stumbling and would not run over 25 MPH without dying.
All 8 plugs broke last fall when they replaced them. Could this be a contributing factor, as in debris falling into cylinder?
Service tech speculated that timing belt jumped a tooth. Not sure how that could happen. Is this a belt drive or chain drive engine?

How sensitive are these engines to overspeed?

$650 or so just to take it apart and see what is wrong.

Truck is a 2004 Lariat with about 160K on the clock.

At what point is it worth a reman and how good are the reman engines? Had a Jasper put into a Windstar some years back and was not impressed with it.

Thanks for any thoughts or comments.

 

This is where a differential compression tester comes in handy. With it you will be able to tell what's bad, rings, intake or exhaust. Then you can go from there. Intake or exhaust means head work. Rings mean bottom end work or a reman. There are some good remans out there. I've never heard anything good about Jasper but that's just me. Check out this post about some of the remans out there,

https://www.ford-trucks.com/forums/1...a-mistake.html

Sometimes the cost of a reworked head is more than a reman. A little research is in order to find what fits your needs. Remember google is your friend.

 

Im not really impressed with remans in general, the one car I had before had a reman in it, it had 16k on it and it ran well......but that is my personal experience. Ive seen a few Ford remans and they were ok, at the time the rebuilder was in St Louis, but now I don't know who does Fords remans......

 

Well talked to Ford again. They suspect bent valves and psossibly damaged cams. For head rebuild they estimate 5K including machining of heads, regrind cams etc.
Reman engine with 3 yr warranty is 7K.
I authorized the 650 to tear it down and confirm actual failure (top end or bottom end).

Probably end up going with a ford reman and run it till it drops.

What a pain.

Appreciate the comments on remans. I don't know who does reman for Ford but as long as there is a warranty I'll live with it and do the recommended maintenance.

I am not a fan of reman in general. I have never understood why they can machine and build a new engine with a warranty life of 60K-100K but remans can apparently only be built with a warranty life of 36K. The iron does not know it is reman.

 

These guys have a 3 year/100,000 mile warrany on their engines. Just sayin'.

Rebuilt engines online from PowerSource

Ford 5.4L Rebuilt engines available online from PowerSource

 

Motorcraft remanufactured engines come with a 3-year unlimited mile warranty. That could be over 300,000 miles of warranty if you drive a lot.

http://www.fordparts.com/products/po...ssemblies.aspx

 

The parts used do reman an engine do know if it is new or rebuilt.

 

I guess my question would be hw did the valves get bent?

 

Well I understand that but my understanding of reman is that all components are new or remanufactured, not just rebuilt with used parts.

Dealer called back. He pulled the valve cover and found broken valve spring and lost keepers. Valve dropped, eventually seized in the guide. He borescoped one of the bad cylinders and says the piston looks beat up pretty bad - his words. He speculates the other cylinder is in similar condition

Looking at a Ford reman engine and a bill of 7400

 

That's disappointing, these engines typically go a lot farther than 160,000 miles. Have you priced a used engine?

Missed this the first time around:

I've never heard of one blowing up as a result of high RPMs. But how would it overspeed? Did your son tune it?

 

No tuning action. I used to work for an engine manufacturer. We saw engines overspeed if used as a brake on a grade. Typically overspeed would get the valves floating, eventually a piston would hit and things would bend.

When I asked the question I did not have the most recent info from the dealer. I have seen a couple other reports online of broken valve springs. Must just be our bad luck.

Thought about used but with no knowledge of the history on a used engine and given the apparent sensitivity of the engine to appropriate service I did not want to take the risk.

 

After posting I went and did a used engine search, and I wasn't impressed with what I found. $2,500 for an engine with 170,000 miles on it probably isn't worth it. Another couple thousand for installation and you're much too close to your figure with a Motorcraft reman.

 

Thanks I appreciate everyone's comments and suggestions.
Always valuable to hear of others experiences.
Hopefully I can contribute more in the future.