4.0 OHV Burning Coolant

[cr_the_machinist]

I have a 1999 Ford Ranger 4x4 with the 4.0 OHV engine that is burning coolant. It a daily driver truck with 73,500 miles on her as of now. Been noticing that my 4.0 has been hungry for coolant the past couple of months and been thinking of taking the weekend off of work and spending it in the garage to solve this problem. I'm thinking of doing a total upper engine rebuild, coming to the conclusion that it is the head gasket that is leaking into one of my cylinders. There is no sign of leaks under the engine or on the engine and it runs like a champ still. I was just wondering if anyone has run into a problem like this one before. The engine runs great but its blowing a small bit of white exhaust (just enough to notice). Finally getting the cash to solve this annoying problem so.... any recommendations or past experiences with this problem?

 

[MAKG]

There are two likely possibilities for burning coolant:

1. Cracked head or blown head gasket
2. Leaking lower intake manifold gasket

The best way to distinguish is a leakdown test. The lower intake will not show up in a leakdown test; a blown water jacket into the cylinder will.

This assumes you are absolutely sure there are no external leaks. Such as, the water pump. Look for corrosion tracks (especially underneath the snout); you aren't likely to see any liquid coolant or steam.

 

[cr_the_machinist]

Yeah, I got the day off of work tomorrow and I was planning on givin' her a good once over under the hood and crawl around in there. I have never seen any leakage at all from under the engine and no witness mark on my driveway either. Figured I'd check it out real good tomorrow and see whats up, top off the system, and get the head gasket and upper engine gasket set and give it a good rebuild. I have had no time what so ever to get this crap done but finally have the bug running though me to fix it. I was thinkin' that I had a minor intake or head leak but I wanna fix it before it progresses to major problem. Thanks for the input, that will be on my check list tomorrow man.

 

[todd_351]

It sounds like I'm fighting the same problem in my '99 Ranger.

It's been drinking coolant for about a year now. A few weeks ago the white smoke got really bad. I took it to a shop and they thought it was a head gasket. They removed the heads and found them cracked between the valves on all cylinders. They wanted $4k for new heads or $7k for a new engine (my motor has 140k miles). I thought that was too much money so I brought the car back and put new heads on it myself. I bought new heads for $575 locally. I got the engine all back together and it still smokes just like before.

Yesterday I pulled the engine apart looking for a cracked block or bad gasket. Everything looks fine. Now I don't know what to do.

I'm curious what you found when you took the heads off your engine and if you eventually fixed the problem.

 

[jds3403]

you need to pull the heads have them inspected for cracks or just look on ebay for new ones (fairly cheap) replace the head gaskets and be done with it. the leak could end up getting bad enough to where it will pour coolant into the combustion chamber and the engine will go into hydraulic lock and bend/break some rods and other internals and then you will be screwed. heads should'nt cost 4k and a new engine should'nt cost 7k. your getting ripped there. i have purchased a set of new heads from a place in alabama off ebay for 500 for both!!! the engine usually runs for about 1000-1500 depending on where you look. just do your research aand it will end up saving your ass in the long run

 

[mhughes165]

It sounds like I'm fighting the same problem in my '99 Ranger.

It's been drinking coolant for about a year now. A few weeks ago the white smoke got really bad. I took it to a shop and they thought it was a head gasket. They removed the heads and found them cracked between the valves on all cylinders. They wanted $4k for new heads or $7k for a new engine (my motor has 140k miles). I thought that was too much money so I brought the car back and put new heads on it myself. I bought new heads for $575 locally. I got the engine all back together and it still smokes just like before.

Yesterday I pulled the engine apart looking for a cracked block or bad gasket. Everything looks fine. Now I don't know what to do.

I'm curious what you found when you took the heads off your engine and if you eventually fixed the problem.

your block isnt level.....common problem, when u do the heads you always need to get the block decked to be 100% sure that the problem is solved

 

[LegacyL22]

I had a similar problem... Ended up being the lower intake manifold gasket. I was losing coolant, and didn't know where it was going...It got progressively worse to the point where it would drip a tiny bit under the engine..i thought i was just a leak from a hose i couldn't get to, so i just kept adding coolan't while waiting for a time i could check it out more closely...Then the smoke started...I got out, looked under it, and coolant was pouring all over the ground. cost $606 to repair. So if you think its that, I would recommend taking care of it while you have the chance.

 

[94 splash]

I had the same thing happen to me was draining the radiator ever other day... the prob was a head gasket and it blew rite between the water jacket and the piston so it was just dumping it into the cylinder the head wasnt cracked or anything i just ended up pulling the engine and did a quick re ring on it and its been perfect ever since do a compression test to see what side it is

 

[RyanD2]

I would like to add to this... I have a 2000 4.0 and experiencing similar problems. However, I do not see any smoke like a few of you have experienced. I would say I've had to add just under a gallon in the past year, BTW, what should the engine temperature be on a daily driver. I've got an aftermarket gauge and it usually reads between 160 - 180 in the summer, lucky if it hits 160 in the winter. I've got 32's with stock gears if that makes any difference.

Thanks

 

[Big Jim M]

Ryan it sounds like you have the wrong thermostat in there OR the one you have is stuck in a partly OPEN condition.. I'd be installing the correct thermostat as your engine is too cold.
As for a gallon a year.. That would hopefully be a very small external leak.. Spend lots of time looking for one single drip from time to time until you find the leak.
Big JIm

 

[RyanD2]

160 - 180 is too cold? I thought that would be a bit high. I know when I flushed everything almost a year ago, I changed the thermostat, believe it was 180 degree. What should be in there? 190?
Thanks Big Jim.

 

[Big Jim M]

I'd always go with a 195* in a modern engine.
Big JIm

 

[AllanD]

your block isnt level.....common problem, when u do the heads you always need to get the block decked to be 100% sure that the problem is solved

Decking the block involves removing the engine from the chassis and completely disassembling it.

It is not normal part of a head job.

AD

 

[94redranger]

Will a bad lower intake gasket show water in the oil? Will a cracked block or bad head gasket show water in the oil? Which one is more likely to show water in the oil? Would a bad intake gasket cause white smoke from the tail pipe?

 

[jagar147]

I would like to add to this... I have a 2000 4.0 and experiencing similar problems. However, I do not see any smoke like a few of you have experienced. I would say I've had to add just under a gallon in the past year, BTW, what should the engine temperature be on a daily driver. I've got an aftermarket gauge and it usually reads between 160 - 180 in the summer, lucky if it hits 160 in the winter. I've got 32's with stock gears if that makes any difference.

Thanks

This could also be a bad rad cap.If your losing pressure your boiling the coolant.For every pound of pressure drop you lower the boiling point 10 degrees.Have the rad cap pressure tested or just get a new one with the correct pressure.Just a thought,most people over look this.