Shall I say frequent misfire 4th cylinder

[moogvo]

Wow, stop leak works just like advertised. Fills any spot where coolant can move thru.
Thanks for the pictures.

Being that you have a OHV, you don't have to worry about any timing chains or anything.
I'd say if you are mechanically inclined at all, this isn't a big deal. If you are going to have to pay someone labour, you have some thinking to do. Its probably not worth it.

Yes... stop leak will stop up the WORKS!

My bad on the engine. Yes, an OHV is not hard at all. I did mine in grass in the front yard with only hand tools. Okay. I DID use an air ratchet and an impact from time to time, but it isn't as if you need a lift or a concrete floor (Although it WOULD be nice!)... If you need heads, I got mine from a place out of Texas called Cylinder Heads International. Both of them were 375 shipped and they covered shipping to send the cores back. No up front core charge. They give you 30 days to ship the old ones back.

 

[Doug.Spencer]

So I pulled the plug tonight and it looks normal. No foul smell, or evidence of coolant burning or smell. My EGR ports have been clogged before and my mechanic back then cleaned them. Should I replace my EGR valve?

 

[herebyproxy]

Check very closely

Look very closely at the insulator between the body and the electrode for a tiny tiny hairline crack.

 

[Dono]

Doug, you will find that crack. Its there.
I couldn't find it on mine, and a respected mechanic couldn't see it either. Believe it or not, my wife pointed it out to me when she was wondering what I was looking at so closely.

Figures.

 

[joe doe]

you want to be looking for this here .my number 4 was cracked as well .too bad i found out after replacing all the head gaskets and such .

i used some crack sealer and it finally must have started working because i dont go thru plugs anymore and the coolant loss is all about done .

for awhile there i was using a plug near monthly and everyone of them would crack .
anyway this is the plug .

Shot at 2010-07-13

get a jewlers loupe if you have too ,but you should be able to see it without one .

 

[gadourym]

I drove mine with the cylinder 4 misfire popping up for over a year and a half, every time the check engine light came on, I replaced that one plug and all was well again... for a while... I was also going through a very small amount of coolant, almost not noticable. Eventually though, the gasket let go, and coolant flooded the cylinder and the engine was toast! Water in the oil, oil in the water, and both in the engine. Unfortunately, I was 250 miles from home, with 3 other people with me when it happened. By some miracle, I was able to get the truck home. I knew the damage had been done, so I pushed it to get home, stopping every half hour to add a gallon of water, just to keep the temp on the right side of overheated. Check engine blinking all the way.

I was able to get a replacement engine, with half the milage installed for not much more than just what it would have cost for head gaskets. So, I'm back in business, and the truck is running like new. Just to be safe, that was the last long trip for the truck. Now I keep it within and hour from home.

 

[Doug.Spencer]

So I changed the oil today, the oil fill cap had yellow watery goo on it and on the walls of fill tube. The drain plug also had it and the oil had some in the bottom of the drain pan after I emptied the old oil. I assume that this is coolant, and that my issue is clear. I'm taking it to a guy to do a compression test to hopefully confirm the crack. I also have a 91 XLT OHV. Would the heads off that fit my 2000 XLS OHV? And if so would it even be worth it to use those instead of new ones?

 

[Dono]

Doug, I'm trying to remember what would happen to your compression. I think it would go down, as the older chambers in the heads are larger. I don't think that's a good idea.

Also, after pulling the old heads you would need a valve job, resurfacing of the heads, valve guide seals.......ah, with the lower compression I just don't think you would be happy, even if the motor was solid when you were done.

 

[herebyproxy]

#4 misfire again

Stopped by the local Advance Auto Parts, bought a couple of SP500 plugs, replaced #4 with one and saved the other one for next time....runs fine again....the last plug lasted about 6 months.

 

[kihei777]

Spark Plug#4 thread dirty

I drove mine with the cylinder 4 misfire popping up for over a year and a half, every time the check engine light came on, I replaced that one plug and all was well again... for a while... I was also going through a very small amount of coolant, almost not noticable. Eventually though, the gasket let go, and coolant flooded the cylinder and the engine was toast! Water in the oil, oil in the water, and both in the engine. Unfortunately, I was 250 miles from home, with 3 other people with me when it happened. By some miracle, I was able to get the truck home. I knew the damage had been done, so I pushed it to get home, stopping every half hour to add a gallon of water, just to keep the temp on the right side of overheated. Check engine blinking all the way.

I was able to get a replacement engine, with half the milage installed for not much more than just what it would have cost for head gaskets. So, I'm back in business, and the truck is running like new. Just to be safe, that was the last long trip for the truck. Now I keep it within and hour from home.

I've replaced my #4 spark plug 2x in less than a year due to a P0304 code. It clears out the code. But I'm curious as to what is causing the code. Closer inspection of the spark plug reveals brown residue on the threads (see pics). I actually have to clean it off with a steel brush just to get it out...not sure if its oil, dirt, coolant, etc. It has the consistency of grime/mud. The actual spark plug looks good except for the threads as depicted on the pics. Any clues? Please help. I surely don't want to get stranded anywhere with a blown engine...was it the lower and upper intake manifold gasket? Please help.

btw, i use Motorcraft sparkplugs...

 

[Dono]

coolant. I lived the same thing. Same cylinder. New head needed

 

[kihei777]

Cracked head or bad gasket?

coolant. I lived the same thing. Same cylinder. New head needed

How do I know if its a bad gasket (so I can just replace the gasket) or a cracked head (which will cost me more since I have to buy a new head)?

Also, how do I perform a compression test and what should I look for? does Autozone/O'Reilly do it for free?

Thanks for the help.

 

[Dono]

When my lower intake gaskets were going I had erratic idle. I never did have a spark plug issue.
With my Cyl 4 crack my idle was fine, but every time I would get hard on the gas, I had to replace thy cylinder 4 sparkplug.

Now, my motor sucked coolant always (I owned it from 34,000 km). I was told that this was normail from the dealership. That turned out to be crap. My motor doesn't suck any coolant now (My coolant resevoir stays at the same level).

What you need to do is a leak down test. With cyl 4 at tdc, you need to push compressed air thru the spark plug hole. Once the cylinder has compressed air in it, you will probably start to see bubbling in the radiator. That will be your answer.

 

[Papa]

Do the simple inexpensive testing first and proceed from there. Water in the cylinder will rust the liner every night and add to your problems like water in the oil so the longer you wait the worse it will likely get. Magnaflux or dye penetration testing of any used head to test for cracks before machining is recommended.