Visible white exhaust (1 Viewer)

[JDNs78FJ40]

I've been driving the 40 around as much as possible and loving it. Engine sounds great at idle but I do get as what I can best describe as a gurggling noise whenever I go up any type of incline in 3rd or 4th gear around 2000 RPM. Will easily do up to 65-70 mph on the freeway, but does lose power on any incline. I have the sniper setup on the original 2F with what I'm guess has 107000 miles and all my sniper numbers are within the appropriate range. I replaced all the engine seals and when we did the compression test a couple years ago I did have lower compression than I had hoped and was very low in 1 cylinder, but decided against a rebuild since I planned on having Cam at Mosley eventually do a cop motor. Coolant was replaced and is still full and appears green and clean and temp runs as high as 200 but mostly sit at 190. I do have to top off the oil now and again due to some leaks here and there. About 2 weeks ago I noticed taking off from a complete stop a big plume of smoke and noticed a hint of it while driving. Now this seems to be the norm. Does this sound like a blown head gasket or is there something else to look for? Would love to drive it as is for a few more years but hate the visible exhaust from a such a beautiful rig..

 

[Curt]

I would keep driving it and keep and eye on your oil and coolant. There are a couple things you can check. Cover your exhaust with your hand, the condensed liquid on your hand will taste sweet indicating coolant. You can open up the coolant resevoir while the engine is running, if you see it bubbling that is exhaust gas.

 

[Dizzy]

It is probably just burning some oil, is my guess.

How do the spark plugs look?

Does there appear to be excessive blow-by evident with oil in the PCV tube?

 

[JDNs78FJ40]

I would keep driving it and keep and eye on your oil and coolant. There are a couple things you can check. Cover your exhaust with your hand, the condensed liquid on your hand will taste sweet indicating coolant. You can open up the coolant resevoir while the engine is running, if you see it bubbling that is exhaust gas.

I’ll check this over the weekend. I read somewhere you can rent some sort of chemical reaction kit to see if the head gasket has failed.

 

[JDNs78FJ40]

It is probably just burning some oil, is my guess.

How do the spark plugs look?

Does there appear to be excessive blow-by evident with oil in the PCV tube?

I’ll pull the spark plugs this weekend and see how they look. What should I look for?

 

[airon23]

I'm watching because my 76 is very similar circumstances. Resealed the engine, runs strong, but I have seen some white smoke I just don't know what it is.

 

[kanzenbach]

I'm watching because my 76 is very similar circumstances. Resealed the engine, runs strong, but I have seen some white smoke I just don't know what it is.

white smoke coolant, black smoke fuel, blue smoke oil, blue smoke at take off from idling, valve seals rule of thumb

 

[Steamer]

white smoke coolant, black smoke fuel, blue smoke oil, blue smoke at take off from idling, valve seals rule of thumb

Just to add, white coolant smoke, or water vapor will disappear soon after leaving the tail pipe whereas oil and fuel smoke linger longer till they dilute with the air. All three have a distinct odor that is hard to describe but once you get familiar with them you can identify them by smell as well.

 

[JDNs78FJ40]

I'm watching because my 76 is very similar circumstances. Resealed the engine, runs strong, but I have seen some white smoke I just don't know what it is.

Did you replace your head gasket? I thought I saw a pic in your thread with the head removed?

 

[airon23]

Did you replace your head gasket? I thought I saw a pic in your thread with the head removed?

Yes I did replace the head gasket

 

[airon23]

white smoke coolant, black smoke fuel, blue smoke oil, blue smoke at take off from idling, valve seals rule of thumb

Just to add, white coolant smoke, or water vapor will disappear soon after leaving the tail pipe whereas oil and fuel smoke linger longer till they dilute with the air. All three have a distinct odor that is hard to describe but once you get familiar with them you can identify them by smell as well.

When you say coolant, you mean coolant mixed in with the oil, i.e. blown head gasket?

 

[Steamer]

When you say coolant, you mean coolant mixed in with the oil, i.e. blown head gasket?

I mean a head gasket failure between water jacket and cylinder.

Oil wouldn't mix with coolant from a bad head gasket. Well,, only if the one & only single oil passage gasket hole from block to head failed but I think that would be extremely rare.

A leak down test would help. That part of the test when you pressurize a cylinder and then listen to the adjacent cylinders with a tube to the ear and into the spark plug holes. Also with each cylinder pressurized you would check for air bubbles in the radiator fill neck. (cap removed).

 

[JDNs78FJ40]

white smoke coolant, black smoke fuel, blue smoke oil, blue smoke at take off from idling, valve seals rule of thumb

The more I look at the exhaust I’m leaning towards blue = burning oil, and it tends to linger a while. I fired her up this evening and took off the radiator cap and let it run for 5 or so minutes and couldn’t see any bubbles. So valve seals are toast? Is it okay to drive or park it till it’s fixed? Is this relatively easy to fix or hire a professional? Really bummed if I can drive it this summer.

 

[KingAir Driver]

I bookmarked this thread when I need to do mine.

Builds - "Scout" the 1977 FJ40

Well, along the lines of... "spending too much time doing something I shouldn't worry so much about"... I decided to take a moment to remove the air cleaner and valve cover in preparation for the valve stem seal replacement. That only took about 2 minutes so I decided to remove the rocker arm...

forum.ih8mud.com

 

[70fj40]

You are going from one worst case (blown head gasket)scenario to (valve seals are toast) another. How much smoke are we talking about? How often have you been driving it? Looking at the plugs would be much more telling than assuming the worst. Take some pictures of your plugs and post them here. That would be a great 1st step. No reason to stop driving it at this point either.

 

[70fj40]

Beautiful rig by the way!!

 

[JDNs78FJ40]

Pulled the plugs tonight and here are the pics. None of them had actual oil on them but a couple are black? Plug 4 is the dirtiest by far.

Does this help narrow down if I’m burning oil? It’s enough of a cloud that when I take off from most stops it’s embarrassing and I need to fix the problem ...

 

[fjc-man]

The easiest stab at this would be to replace the valve stem seals. If you were to do a cylinder leakage test on #4 and the results Showed minimal leakage, the oil consumption could still be stuck oil control ring also known as the “scraper”. If that was the case, you’d be pulling pistons.....

 

[JDNs78FJ40]

The easiest stab at this would be to replace the valve stem seals. If you were to do a cylinder leakage test on #4 and the results Showed minimal leakage, the oil consumption could still be stuck oil control ring also known as the “scraper”. If that was the case, you’d be pulling pistons.....

Thanks. I’m going to buy some valve stem seals and give that a go. It can’t hurt and doesn’t seem too bad to replace them and if it solves 90% of the problem and gives me 5k-10k more miles I’d be more than happy . Thanks for the input.

 

[pb4ugo]

Just do a dry and wet compression test on #4. That should confirm seals or rings. I'd do all the cyldrs while your at it.