I picked up a 97 ranger 2.3l with 5 speed last week. It has 117k miles on it and I don't know the past history. I do know that it had a starting issue where if eventually you cranked it over for long enough it probably would start. The guy I got it from said he put a new fuel pump in it so it has that going for it. I found that it had either the wrong computer or bad computer in it. I replaced that with the correct one from a junk yard and started right up. Drove and ran pretty good. Didn't seem like a lack of power but I'm use to driving a 3 cylinder honda insight. Anyways I did a compression test today and Cylinders 2-4 had 170psi and cylinder 1 had 100. Now I did it on a cold engine and hear you should do it on a warm engine but can't see it making up that difference. I also read it's probably not a head gasket as it won't be that low. I've watched a couple videos and looks like some of these had valve issues. I'm just wondering if there's something else I should check first before pulling the head? The reason I did the compression test is that...there was a slight noticeable miss at idle and really noticeable when the ac was turned on. Thanks for any help tips or tricks. If the head has to come off anything else I should be doing while I'm in there?

 

Cold compression test is always first, so you did good
Warm engine test is done if no issues are found cold, when parts are warmed up it can show a leak in a failing cylinder that's not there cold

You can do a WET test on #1, add a teaspoon of oil then re-test, pressure will go up a little, but if it doesn't go up to above 160psi then its a valve issue

And at 100psi it most likely is a valve issue, but..............these engines are known for rocker issues, so once you get valve cover off you may see the problem, a rocker has slid off to the side so valve is either not closing all the way or intake is not opening all the way or long enough
My money is on a rocker issue since 2-4 test at 170psi
So you may not have to dig that deep

If you have an air compressor and fitting for spark plug hole, you could put #1 at TDC and pump air into it and then listen at tail pipe, burnt exhaust valve would let out alot of air
But if its not a rocker issue then head would have to come off in any case so.............why test for that

 

Thanks Ron, I did the wet test and it was roughly the same so it must be valves. I was really hoping it was going to be a rocker issue but the rockers are straight on place so I suppose the head has to come off. Bummer. I really do appreciate the help and tips! Thanks

 

Yes, Bummer indeed

Thanks for the update

When you get the head off if that #1 piston look pitted or valve is burnt then #1 fuel injector may be bad, causing #1 to run Lean, so a bit of pinging/knocking, which leaves pitting usually and also cause extra heat so can cause burned exhaust valve
It can also "tulip" an intake valve but you would usually hear "popping" noise when running

Point being, its good to find the reason #1 lost compression

 

Ok, so I finally took off the head. This is the first head I've ever pulled so I don't know that much. Didn't realize it was going to be so much work. Figured a little 4 cylinder should be a few items but seemed like quite a bit. Anyways I noticed a crack between the two valves. Not sure if that's my problem or not. Also the two valves are a different reddish color compared to the other valves. Not sure if that's what's considered a burnt valve. I'll see if I can figure out how to post up a picture here.

 

 

I have a fuel injector flow bench I can hook them up and see what they look like. See if there's something wrong with number 1 injector. Also with this other computer in it before. I don't know how long someone ran it like that or why they put it in ect. Maybe the PCM wasn't telling it fire correctly? Sure it doesn't happen overnight and must be ran for awhile to do it would be my guess.

Also what would a typical valve job cost or what should I expect to be looking at here near San Francisco?

 

Yes, you have a cracked head, you will need to get a new one, 1995-2001 2.3l or 2.5l head will work

Generally cracked head is from being overheated too long, i.e. temp gauge goes above 3/4 and you try to "make it home"

But could be a casting flaw, a goof when head was cast with molten metal, it has a weak spot and one day............it cracks

 

So with the crack is it not fixable? I hear that they use to drill a hole, insert a stud and grind it back down to the original size.

 

Well, yes, if this was a rare motor and heads were no longer available for it then trying to fix it might be the only option

The longevity of a fix like that is questionable unless you get the head completely tested, Magnaflux, and pressure tested
A new 4cyl head might cost $500, you may be able to fix it and test it, then surface and clean it for $350
So you saved $150
And then in 6 months another cylinder cracks..................and your time, gaskets and new head bolts aren't free, its more of a roll of the dice than a new head.

 

Thanks for all the help RonD! I really do appreciate it. Yes, I just looked on rockauto for a head. Looks like it's either 380-440 for a rebuild head with valves and cam no cam seal. Looks like the cheapest I've seen so far. Any reason not to go through them or another route that you might know of?

 

That price would be if you had a core to send them back, with your head being cracked, I don't think you have a core.