Toyota 4Y – Forklift Engine Smoking Problems

[Mark Taylor]

Ok, so I know my problem isn’t exactly with a car, but it is an internal combustion engine and everything works pretty much like it does on a car. The fuel is just LPG and not gasoline or diesel. It’s an old Toyota 4Y engine, with a carb, circa 1993-1998. The engine is used approximately 6 hours per month for usually only a few minutes at a time. 7800 hours on it currently. Recently, I noticed some smoke coming out of the exhaust pipe. Very little to none on start-up, but gradually becoming worse over a few minutes until it started becoming too thick to even see within 5 minutes. I started to pull the plugs to look at those just to get an initial inspection, saw the #2 well full of oil. Pulled the plugs, they all looked pretty worn, #4 plug had blackish gunk on the threads. #4 plug also felt like it had been cross-threaded at some point.

I decided to replace the plugs, wires, distributor cap, and rotor (it had been having misfires and running rough, so I figured why not, these parts are 10 years old at least anyway). I replaced the spark plug tube gaskets as well, due to the oil leaking into the tube. I also did a compression test at the same time to make sure the threads on #4 weren’t too buggered. Results were 1: 170, 2: 170, 3: 170, 4: 165, all dry, didn’t have any oil to do a wet test. After completing all of this work, I started her up and ran her for about 5 minutes to make sure the ignition was working ok and to assess the smoking further. After about 3-4 minutes, the smoke came back. This time, I noticed it coming out of the #4 ignition boot as well. It was also pulsing out of the boot in time with the engine.

I will also note that I pulled the engine dipstick to inspect the oil. The level was good, but it had a definite, slight milky look to it. I wiped it off, stuck it back in and pulled it again. Again, it looked a little milky. I pulled the radiator cap after the engine had cooled down a while and there was no coolant in the radiator, but the overflow bottle was full. I also noticed that it looked like some engine oil was seeping out around the intake manifold.

I appreciate any insight anyone could give me as to where to go next with this. Given the age of the engine, I don’t want to just start opening things up without some more feedback on it. Again, I know it’s not a car, but it works exactly the same so I figured it was worth a shot. Thanks again!

Topic

[college man]

I’m not a fork lift mechanic by any means. Sounds like your running rich/ mixture or
your rings are passing with blow by and burning oil. Your best bet is to get a good
service manual for settings and adjustments. so things can be set up and checked.
Lastly air filter clean?

[Jim Davis]

On the smoke out of the exhaust, is it a bluish color or more of a white, and does it have a as I always thought of it, a sickly sweet smell?

[Mark Taylor]

I did manage to find a complete service manual but haven’t had a chance to read through it in detail yet. The air filter is brand new. I would certainly believe that some things require adjusting on it and I’ll look into that as well.

The smoke was more white in color. Didn’t smell “sickly” sweet but it is LPG exhaust we’re talking about and not gasoline. I would say it was on the sweet smelling side of things though, and definitely whitish in color.

[Jim Davis]

White exhaust and your coolant dissapearing, sounds like a blown headgasket. You still could have gotten good compression readings. You can get a kit from napa or possibly other parts places to do a test for combustion gases in the radiator.

[Mark Taylor]

Thanks! I’ll see if I can pick one up and test for that. I’ll let you know what the results are. I was wondering if it could be a head gasket despite my compression readings. Guess we’ll find out. Thanks, again!

[Its me]

I’ll concur with Heavyj. You can have an issue with the head gasket and coolant can get into the cylinder and mix with the oil and not get oil into the cooling system..

Also, while it may be a head gasket, it can also be a physical issue with the head (cracked or have eroded coolant jacket passages).. as well as an issue with the block itself…

Here is a pic of a bad toyota head I had to replace..

Good luck

Karl

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[Mark Taylor]

Thanks guys. Figured I’d just update the topic for some closure. The head gasket ended up being the problem. Replaced it (along with several other gaskets that came in the kit) and the engine is running very well now. Starter was bad too and I replaced that last week. The unit is running very well and I expect it to continue to do so for a while.

Thanks again for your input. Here are some pictures in case any of you are curious.

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[college man]

Glad you worked it out. 🙂

[Tammy]

I know this has nothing to do with your conversation. But I need Help. I was doing a google search on fumes from forklift, and I came upon this forum. I joined just to get answers. Please help me. Where I work their are Toyota forklifts. I know their is at least one putting off this sweet sickly smell, that is making me deathly sick. They told me to let them know which one. It’s like really? But I’m sure I can. But if you can tell me what is going on with it. I can give them more Info. The fumes don’t smell of rotten eggs, like most do. This is sweet, but sickly. I truly believe it is also a health hazard. I get home from 10 hours at work, I can still smell it. Please help, and Thank You in Advance.

[Tammy]

So the forklift I’m speaking of with the Oder, could be head gasket?

[Lissa]

So main problem is in starter. Glad to know you get rid from this problem and provide us information.

[Author]

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