M35A2 low power, white smoke & rough idle

[Cantrade]

I use my 1968 Kaiser Deuce to haul a 1000 gallon water tank. I can usually make it up the hill between the water source and our place in 2nd gear but last week I had to downshift to 1st and I noticed a rough idle and white smoke from the exhaust. The engine is a LDT-465-1D that was overhauled in 1989. Truck shows about 22,000 miles but who knows? The problem seemed to be getting worse so here is what I have done so far.




Troubleshooting to date:

1. Changed primary, secondary and final fuel filters. No water found in canisters.
2. Tested fuel pressure with electric pump running: 5.5 psi at bleed screw between secondary and final filters.
3. Pulled in-tank pump and cleaned screen. No problems here.
4. Adjusted valve lash. .010” Intake & .025” Exhaust. None were very far out of tolerance.
5. Tested injectors by loosening fitting while engine running. Cylinders dropped about the same rpm.
6. Removed injectors and pop tested. These are AMBAC P/N: AKN-130SM-6844-B2 and the specification sheets say they should open at 3600-3750 psi Mine opened around 3450 psi and I figured that they had taken a “set” and I adjusted them to 3500 psi. One injector seemed to not seal itself properly and I took the nozzle apart and cleaned it well and retested. It worked then.
7. Removed the center bolt from the hydraulic head and inserted a plastic pen to use as a travel indicator. It moved up and down as the engine was turned over by hand so I think it is free.
8. Removed the cover of the fuel shut off lever on the injection pump and found the red mark was where it should be. (Nothing has ever been touched on the IP and it was working well prior to this problem.) There was engine oil in the cover. Is this normal?
9. The FDC is supposed to have been bypassed but the fuel lines are terminated in the stock place and from the “tee” on the FDC a fuel line goes to the input port of the HH. None of the overflow lines have been blocked.
10. The IP has been replaced according to the PO and it looks clean as a whistle inside.
11. I checked for water in the oil and oil in the water as well as fuel in the oil. Nothing evident of anything wrong here. (I only drive this truck about 20 miles each month so this could be a not valid test right now.)
12. I removed the inlet to the turbo-charger and found the blades intact with no noise and no play in the shaft. The air and exhaust passages are all clear. There is no muffler.

It is beginning to look like I may have a blown head gasket.

1. Could a gasket blow and not have any of the usual indications?
2. I have seen threads that say the white smoke is caused by over-fueling the engine and other threads say that over-fueling causes black smoke. Anyone know which is right?
3. Where can I get the special 7/8” wrenches required to remove the head stud nuts?

Thanks for reading my tale of woe!!

 

[gringeltaube]

Usually when a MF head gasket failed you would have some visible signs like fluids running down on the outside of the engine(block). And you would have compression loss in one or maybe two cylinders but never affecting all 6 cylinders equally.

You say the red mark was where it should be, but that mark is more for a reference. Did you actually check the correct timing, by comparing the line on the damper with the pointer in that little window, on the IP?
I'm asking because white smoke can (also)come from a retarded ignition. Just an idea, but what if the three cap-screws on the IP drive gear came loose somehow?



G.

 

[gimpyrobb]

Have you pulled the air filter and washed it?

I did this with my 5ton and it helped a little, then I tried a newer one a buddy had and it made a huge improvement. Seems they don't last forever!

 

[63C20]

Water entering combustion will create white smoke. Faulty head gaskets and cracked cylinder heads or blocks are a common cause
9 times out of 10 it is the head gasket (I would say 100% but I wanted to leave myself some wiggle room) it is leaking coolant into the cylinder on the intake stroke. It doesn't take very much to cause rough running and a loss of power (and the white smoke). You may see some bubbles in the coolant if you check while it is running and some loss of coolant. Unfortunately it will only get worse and there may be erosion of the block or head (Bad). We would see this back in the day and we would swap out the engine and send it to depot. Unfortunately most of us don't quite have that level of support for our Green Iron. I would investigate a good used engine unless you want to pull the heads to confirm the diagnosis, in any case a used engine may be more cost effective (and cheaper) than redoing the head(s). I have a spare long block just in case evilness happens to one of our trucks.

White smoke also may occur from unburned fuel entering the exhaust system, but it sounds like you have eliminated that issue.

Attached is what I think is your problem FWIW YMMV

Good luck

 

[The HUlk]

white or blue smoke from a combustion engine usually indicates oil is burning. Black smoke usually indicates fuel is burning. Diesels & two strokes can be tricky because the fuel contains oil.

 

[The HUlk]

Water entering combustion will create white smoke. Faulty head gaskets and cracked cylinder heads or blocks are a common cause
9 times out of 10 it is the head gasket (I would say 100% but I wanted to leave myself some wiggle room) it is leaking coolant into the cylinder on the intake stroke. It doesn't take very much to cause rough running and a loss of power (and the white smoke). You may see some bubbles in the coolant if you check while it is running and some loss of coolant. Unfortunately it will only get worse and there may be erosion of the block or head (Bad). We would see this back in the day and we would swap out the engine and send it to depot. Unfortunately most of us don't quite have that level of support for our Green Iron. I would investigate a good used engine unless you want to pull the heads to confirm the diagnosis, in any case a used engine may be more cost effective (and cheaper) than redoing the head(s). I have a spare long block just in case evilness happens to one of our trucks.

White smoke also may occur from unburned fuel entering the exhaust system, but it sounds like you have eliminated that issue.

Attached is what I think is your problem FWIW YMMVView attachment 585993

Good luck

Sometimes a leaking head gasket or block/head damage will cause the engine oil to look like chocolate milk from coolant entering the block.

Compression test will answer alot.

 

[Cantrade]

Water entering combustion will create white smoke. Faulty head gaskets and cracked cylinder heads or blocks are a common cause
9 times out of 10 it is the head gasket (I would say 100% but I wanted to leave myself some wiggle room) it is leaking coolant into the cylinder on the intake stroke. It doesn't take very much to cause rough running and a loss of power (and the white smoke). You may see some bubbles in the coolant if you check while it is running and some loss of coolant. Unfortunately it will only get worse and there may be erosion of the block or head (Bad). We would see this back in the day and we would swap out the engine and send it to depot. Unfortunately most of us don't quite have that level of support for our Green Iron. I would investigate a good used engine unless you want to pull the heads to confirm the diagnosis, in any case a used engine may be more cost effective (and cheaper) than redoing the head(s). I have a spare long block just in case evilness happens to one of our trucks.

White smoke also may occur from unburned fuel entering the exhaust system, but it sounds like you have eliminated that issue.

Attached is what I think is your problem FWIW YMMVView attachment 585993

I am really starting to think you may be right. This problem is getting worse which is consistent with a small leak getting washed out and leaking more. I wish I had other indications like bubbling in the radiator or water in the oil or oil in the water, etc.

 

[Cantrade]

Not sure what is happening to my responses to the posts so I will try again.

gringeltaube: Here is the way I checked the IP. I rotated the engine clockwise until the timing marks on the damper lined up with the pointer that is visible under the air compressor. I removed the small rectangular cover from the front part of the IP and looked straight down into the unit. The two lines were aligned. I then removed the cover from the shut-down lever and using a mirror tried to locate the red tooth. It was not visible so I rotated the engine until it came into view. I think I was not on the #1 cylinder and will do this again with the valve cover off to make sure.

gimpyrobb: I did check the air filter element and it looks real good and does not seem dirty. I tapped it and not much came out. I also have a restriction indicator that never gets off its lowest level so I'm thinking the inlet path is o.k.

TheHulk: I do not have a compression gauge of the proper range. This is my first attempt at repairing this type of engine and most of my stuff is for smaller, lighter equipment. (Switching out a block would be a major PITA for me to attempt.)

 

[gringeltaube]

OK, I agree, timing is not the problem.
But, following 63C20's theory, if what you are "burning" is coolant then it should at least smell like it, and you sure had to replenish the radiator already?


G.

 

[Cantrade]

Yeah, if I only had some supporting evidence of coolant in the combustion I would be able to proceed. This thing is running so rich that in a couple of minutes it fills my 1000 sq ft shop with smoke and you can't stay in there because your eyes burn too bad. It's a wonder that someone has not called the fire dept. because of the smoke when I test the deuce. I have not added any coolant to the truck for a couple of months and then only because I had the radiator out while working on the alternator.

I am trying to figure out a way to use air to pressurize the cylinders and watch the radiator for bubbles. I need some rig to seal in the injector nozzle hole while the cylinder is on TDC of the compression stroke. If the air leaked into the cooling jacket it should bubble up in the radiator.

 

[Valence]

Would you see the "chocolate milk" look of the oil with coolant in it if you were to pull the oil fill cap on top and look inside with a flash light? Perhaps right after running?

 

[Cantrade]

I just had the valve covers off and it is clean as a whistle in there. No milky foam collected on anything. It looks like this engine just went together after a rebuild. That's the problem there are no other symptoms of a head gasket leak. But, I don't drive this truck much so it could still have a dead cylinder or two and not have many other signs. I am thinking of bypassing the FDC to see if that has any effect on the running of the engine. I looked at a couple of you-tube movies where a couple of guys had good luck doing that.

 

[Cantrade]

New development. I rechecked the IP alignment today just to be sure all the indicators were in the right place. In order to do this I took the front valve cover off and watched the valves for #1. Sure enough, when the timing mark on the damper was lined up so were the two marks before the Ip. The red mark on the gear in the HH was right on too.

I also decided to take some of the advice received here and took the air cleaner element out and ran the engine. It did not run differently but I let the engine warm up and was looking around to try to isolate which cylinder was the bad actor. I listened to all of the injectors click with a metal rod and they all sound the same. As I was looking at the exhaust side I noticed the rear of the engine "sounds" louder and I suspect the bad cylinder is #6. Also, the exhaust manifold near that outlet was quite a bit cooler than the others. I could touch it even after a few minutes of running.

I still had the air cleaner off and noticed that when I put my hand near the opening there was pulsating air flowing out of the opening. I thought there should be suction there and not an outflow. So, I am thinking that I have a burned inlet valve on #6 and even if it fires poorly it is back feeding compression pressure into the inlet manifold and out through the turbo and air inlet. Since the turbo is basically out of the picture at idle I suppose there might be enough pressure to back flow the inlet flow whenever the cylinder fires. With the air cleaner housing and filter element installed you would never notice this.

Am I totally FUBAR on this theory.

 

[The HUlk]

Would you see the "chocolate milk" look of the oil with coolant in it if you were to pull the oil fill cap on top and look inside with a flash light? Perhaps right after running?

Usually just pulling the dipstick will tell. After water in the crankcase gets mixed up by the crankshaft the oil will look like chocolate milk instead of like new or used oil.

 

[The HUlk]

New development. I rechecked the IP alignment today just to be sure all the indicators were in the right place. In order to do this I took the front valve cover off and watched the valves for #1. Sure enough, when the timing mark on the damper was lined up so were the two marks before the Ip. The red mark on the gear in the HH was right on too.

I also decided to take some of the advice received here and took the air cleaner element out and ran the engine. It did not run differently but I let the engine warm up and was looking around to try to isolate which cylinder was the bad actor. I listened to all of the injectors click with a metal rod and they all sound the same. As I was looking at the exhaust side I noticed the rear of the engine "sounds" louder and I suspect the bad cylinder is #6. Also, the exhaust manifold near that outlet was quite a bit cooler than the others. I could touch it even after a few minutes of running.

I still had the air cleaner off and noticed that when I put my hand near the opening there was pulsating air flowing out of the opening. I thought there should be suction there and not an outflow. So, I am thinking that I have a burned inlet valve on #6 and even if it fires poorly it is back feeding compression pressure into the inlet manifold and out through the turbo and air inlet. Since the turbo is basically out of the picture at idle I suppose there might be enough pressure to back flow the inlet flow whenever the cylinder fires. With the air cleaner housing and filter element installed you would never notice this.

Am I totally FUBAR on this theory.

I would guess the cooler exhaust manifold is due to lack of firing in that cylinder with the cause being not enough compression. The rough running is because of misfire of at least that cylinder throwing the engine out of balance. The head needs to come off and inspection performed to know exactly what is wrong and if it can be repaired while in the vehicle or not.

 

[Cantrade]

Exactly my thoughts about the symptoms. I will attempt to pull the heads tomorrow. I will need to get some gaskets, etc. Around here, central NM, the possibility of doing that is nil.

 

[Tracer]

Sounds like a possible head gasket problem. Wish you the best and hope you don't have something more serious.

 

[The HUlk]

Exactly my thoughts about the symptoms. I will attempt to pull the heads tomorrow. I will need to get some gaskets, etc. Around here, central NM, the possibility of doing that is nil.

post up in the parts wanted classified.

 

[63C20]

Let us know what you find. If the head gasket is blown like that picture I posted, you would not see the "milkshake" in the oil, Thinking about it...... a bad intake valve might exhibit similar symptoms, although I think it might be less likely. Those engines are pretty tough, in their own fragile way. as I recall, the valves were not a big issue until the hours started piling up. Sounds like you don't have a high hour engine. A head gasket can go out early on, especially if maybe it was not installed quite right (don't ask me how I know).

Good luck

 

[Cantrade]

I see Memphis Equipment has a head gasket set for around $267. They will probably get here by the time the heads are back from the machine shop. I have difficulty with the burned intake valve idea and instead am thinking that it might be something else that is interfering with the valve closing. Maybe a cocked seat or sticking valve guide. I have seen lots of burned exhaust valves but not so many intake valves. I plan to check the valve clearance again prior to pulling the head.