Head Rebuild @ 250K Miles

[TTurner161]

Im currently in the process of replacing my timing belt on my 98 ranger with the 2.5 liter. The pickup has a little under 250k miles and I figured since I'm going this far into the engine, I might as well pull the head, clean it up and take it to a machine shop to check it out and re-seat the valves and replace any worn parts. I figured it was good insurance since there is only a few bolts left holding the head on after i remove the belt, so I tell my dad my plan and he says not to do it. He says the freshened up top end will put to much pressure on a 250,000 mile old bottom end and cause it to blow soon after. I asked the same question to a family friend who is a heavy equipment mechanic and got the same answer. Yet i read on here earlier that it shouldnt be an issue. I would like to hear your opinions on if I should pull the head or just leave it alone and drive it, and your reasons why.

 

[Mark_88]

I had the head on my 2.0 done and the bottom end went about 1,000 Km after that...and the bottom end had less miles than yours does...about 360,000 km (roughly 200,000 miles)...

It might be ok if you don't push it...like I did...figured with the racing cam and the new head I could wind it out...not a good idea...

 

[TTurner161]

Oh wow. That really didn't last that long at all. I wont be putting any performance parts in it though. Just replacing worn parts with stock ones

 

[fastpakr]

Do you have a particular reason to assume the head needs rebuilding? I certainly wouldn't be pulling the head off based purely on mileage when replacing a timing belt.

 

[Mark_88]

Do you have a particular reason to assume the head needs rebuilding? I certainly wouldn't be pulling the head off based purely on mileage when replacing a timing belt.

Good question...mine had to be done due to excessive blow-by...and if yours is otherwise working I'd just replace the timing belt...

 

[TTurner161]

Do you have a particular reason to assume the head needs rebuilding? I certainly wouldn't be pulling the head off based purely on mileage when replacing a timing belt.

No other reason than the high mileage really. And the fact that its not going to require much more labor to pull it.

 

[Bryan22]

I'd do a compression check on it. If compression is up and pretty even across all 4 cylinders, just replace the belt and run it. That's just me though.

 

[dorman68]

No other reason than the high mileage really. And the fact that its not going to require much more labor to pull it.

I would just leave it alone. These engines are not known for premature head failures such as cracking, warpage, guides, head gaskets. If this engine has a good maintenance history there is no reason why it won't run another 100,000 miles with proper care.

 

[TTurner161]

I went ahead and just changed the timing belt and tensioner pulley. Man it was a PITA without that tensioner tool, there isnt to many places to get a pry bar in.

Also it seemed as though the back timing cover that the timing marks are on was cracked close to the triangle mark for the cam, it looked like maybe it was spread from its original position. I couldnt ever get it directly on the mark no matter how many times I turned the motor over or rotate the cam +/- a tooth in the belt. The cam just always seems to be a tooth off. I guess I'll just get it back together and see how it runs. Hopefully I don't have to tear all the way back into it.

And as far as a long term project, I'm thinking of just buying a rebuilt long block 2.5 and assembling a engine to just swap out. I really like the truck and its paid for so this may come handy for when those high miles eventually do cripple the little pickup

 

[TTurner161]

I forgot to mention that a compression test was done whilie diagnosing the timing belt issue and it was fine.

 

[kevinsranger]

I went ahead and just changed the timing belt and tensioner pulley. Man it was a PITA without that tensioner tool, there isnt to many places to get a pry bar in.

Also it seemed as though the back timing cover that the timing marks are on was cracked close to the triangle mark for the cam, it looked like maybe it was spread from its original position. I couldnt ever get it directly on the mark no matter how many times I turned the motor over or rotate the cam +/- a tooth in the belt. The cam just always seems to be a tooth off. I guess I'll just get it back together and see how it runs. Hopefully I don't have to tear all the way back into it.

And as far as a long term project, I'm thinking of just buying a rebuilt long block 2.5 and assembling a engine to just swap out. I really like the truck and its paid for so this may come handy for when those high miles eventually do cripple the little pickup

you couldnt get the cam to line up with the timing mark? what do you mean? like you set it and because of the valve springs it made it rotate a tiny bit? because if thats the case you need to hold it lined up and slide the belt on

 

[TTurner161]

you couldnt get the cam to line up with the timing mark? what do you mean? like you set it and because of the valve springs it made it rotate a tiny bit? because if thats the case you need to hold it lined up and slide the belt on

No the cam was able to spin easily for those few degrees where the timing mark lines up. I was just saying that I couldn't get it lined up as perfect as I would have liked even after adjusting the cam a tooth in either direction. This was either due to the cracked plastic cover that the timing marks are actually on or some other reason yet to be discovered. Ill find out once i get everything re-assembled though

 

[Bryan22]

I've never been able to get the cam mark to line up right on the money. Just make sure it's as close as you can get it, and it should be fine.

 

[v8318cid]

Rumor has it the 2.3 (and the 2.5 if its based upon the same design) is next to impossible to line up timing-wise. Always about a half-tooth off. Not sure why... I've heard people say just turn the cam sproket 360 degrees to fix it, but wouldn't that just put the cam back in exactly the same place?

 

[fastpakr]

There is nothing whatsoever difficult about timing the 2.3/2.5 Lima engines. The only RBV engine I've heard of being a problem is the SOHC 4.0.