UPDATE: I bought the truck. See post #6 for more details.



I'm looking at buying an 01 quad cab 4x4 w/ about 150000 miles. It's got a 4.7 in it with a bad valve seat on one cyl.

What do you guys think I could get away with as far as a repair. If I buy it I'm debating between swapping in a ramanned engine or just doing some head work. Do you think that a block with 150K on it would do well with a set of performance heads and a tuner?


And do you have any tips on a good place to get a new motor or new heads (stock or performance)?

 

As long as the lower end is fine I'd swap the heads, put on a new timing set, and call it a day. If you can, pick up some heads at your local boneyard, and rebuild them before you put them back on.

If you have any doubts go remanned. Some guys like Jasper but check around, there may be some shops near you. Make sure it is fully warranted. One caveat, if you do decide to swap the engine make sure that it has the 16 tooth tone ring. You have the early JTEC style engine controller. Later models use a 32 tooth that is not compatible.

 

OK, thanks.

Does the 4.7 respond well to porting and polishing the heads?

And I don't even know what that second paragraph means, but I'll make sure to do my research before diving in that deep. I appreciate the heads up

 

It may not have a bad valve seat. These 4.7s were known to kick a rocker arm off here and there.

 

I haven't looked at it myself yet, but the guy selling it said that the dealer pulled the valve cover and found a bad valve seat on cyl #2.

A rocker arm wold be much easier to repair though right?

 

I just bought this truck for $1800. Now I need to figure out the best course of action to get it running again.

This is what the service tech working on it had to say:


Compression test showed:

1 - 120
2 - 0
3 - 150
4 - 120
5 - 150
6 - 150
7 - 12
8 - 135


I won't be able to work on this until at least next week so I'd like to do my homework on what to look for before then. I'm planning to pull the head and inspect the block and pistons. I just have a few questions though...

1) Can a dropped valve seat cause bottom end damage?
2) Is the low reading on cyl 7 possibly due to the problem with the valve on #2 or is that another problem?
3) With the way the rest of the compression numbers look do you think a simple head swap would be good or should I be looking at a full long block?

 

Kind of feels like it was ran low on oil to have this kind of damage so you may have other damage as well.


I say a complete rebuild locally or order a long block

 

Or it was overheated.

1. As long as the piston isn't hitting the valve there shouldn't be any bottom end damage, from the valve.
2. The valves in one cylinder will not affect another. They aren't even next to each other. You have another problem.
3. Can't tell. The compression numbers won't tell us how the bearings/bottom end is.

 

OK, thanks. So where is cyl 7? Is that even on the same side of the engine? I don't have the FSM for this yet

 

Here you go!