Cloud of white smoke from exhaust (1 Viewer)

[HuyFZJ80]

Sorry all, but I’ve just read 20 “white smoke” threads and none seems to have the same symptoms.

Previous to all this, there was just the normal amount of white smoke in the mornings during cold starts, assumed to be condensation/normal LC stuff. I did add some Lucas fuel system treatment the week before, but have since filled the tank again with gas.

Last week, it struggled to start once, then a large amount of white smoke came out of the exhaust. Enough to create a smoke screen that even James Bond would be proud of. Ever since then, she’s been smoking at least double the normal amount. Seems to be white smoke. I don’t seem to be losing coolant. No loss of power. Oil from the dip stick still looks good and not milky. The oil cap did have some milky residue but I think that’s attributed to the frequent short drives. Did a block test on the radiator and it passed. I pulled the spark plugs and they all look pretty normal except #6 is a bit darker than the rest. I’m planning on sending an oil sample to Blackstone this week. Could this be caused from the fuel treatment I put in a week before this started? Any suggestions would be appreciated on what this could be.

I’d be ok with this if she had just started on a cold day. Pics below are after ideling 20 minutes and fully warmed up. It does get a bit better after driving.

 

[efjayatee]

That white smoke doesn't look normal-its thick. On cold mornings mine lets out smoke but not at all like yours and I had my HG 12k miles ago. Get yourself a scan gauge since its is an OBD2 to monitor your ECT.
White smoke almost always indicated to oil being burn off, whether internally or in exhaust. Hate to say but it could be your seal(s). How many miles is on the 80?

 

[HuyFZJ80]

It’s a 94’. OBD1 unfortunately, sure do wish it had OBD2 as it would make it easier to figure out what’s going on. I’m keeping an eye on my oil levels in the meanwhile til I figure things out.

 

[HuyFZJ80]

That white smoke doesn't look normal-its thick. On cold mornings mine lets out smoke but not at all like yours and I had my HG 12k miles ago. Get yourself a scan gauge since its is an OBD2 to monitor your ECT.
White smoke almost always indicated to oil being burn off, whether internally or in exhaust. Hate to say but it could be your seal(s). How many miles is on the 80?

I bought this truck just a couple months ago. Has 250k on the body. PO had a local shop put in a remanufactured motor in around 40k miles ago.

 

[efjayatee]

Well that sucks.....he provided you with paperwork, receipt...ect. Was it a rebuild or a refresh? How does the exhaust sound? Could be an exhaust leak.

 

[efjayatee]

It’s a 94’. OBD1 unfortunately, sure do wish it had OBD2 as it would make it easier to figure out what’s going on. I’m keeping an eye on my oil levels in the meanwhile til I figure things out.

You can install a temp sensor on your rad hose. Or get yourself a TOYOBD1. Goggle it_ it's a scan gauge for 93/94 w/obd1. Can read your ECU and also ECT
Don't rely on the factory temp gauge. Once it moves towards ref, it's too late.

 

[Outsane]

I would test for head gasket issues..does the plume if smoke smell sweet?

Get the kit that looks for exhaust in the radiator fluid.

Good luck

 

[HuyFZJ80]

You can install a temp sensor on your rad hose. Or get yourself a TOYOBD1. Goggle it_ it's a scan gauge for 93/94 w/obd1. Can read your ECU and also ECT
Don't rely on the factory temp gauge. Once it moves towards ref, it's too late.

Thanks. I’ll look into this.

I would test for head gasket issues..does the plume if smoke smell sweet?

Get the kit that looks for exhaust in the radiator fluid.

Good luck

The exhaust fumes smell like exhaust fumes. Kind of harsh, fuel smell. Definitely not sweet. I’ve done the block test with the radiator and it passed. I’ll be keeping an eye on the radiator fluid levels though in case things change

 

[Brindleboxer]

I would question the fuel ratio but on the pre-OBDII trucks its harder since you can't scan real time. If I was in your shoes I would try and eliminate the easiest things first. You said #6 plug was darker than the rest, swap plugs and let run for a bit and see if it fouls. If it does I would lean toward checking that injector circuit.

Did you check to ensure there are no codes present?

 

[HuyFZJ80]

I would question the fuel ratio but on the pre-OBDII trucks its harder since you can't scan real time. If I was in your shoes I would try and eliminate the easiest things first. You said #6 plug was darker than the rest, swap plugs and let run for a bit and see if it fouls. If it does I would lean toward checking that injector circuit.

Did you check to ensure there are no codes present?

Appreciate the recommendations. I’ll get the spark plugs swapped out today, just gotta grab some from Mr T. How would you go about checking the injector circuit? Send them in somewhere for a test/rebuild? Also, no CEL so I’m not entirely sure how to check codes. The CEL bulb definitely works as it comes on during initial start up. Thx!

 

[Fj80oregon]

Appreciate the recommendations. I’ll get the spark plugs swapped out today, just gotta grab some from Mr T. How would you go about checking the injector circuit? Send them in somewhere for a test/rebuild? Also, no CEL so I’m not entirely sure how to check codes. The CEL bulb definitely works as it comes on during initial start up. Thx!

Do you have a FSM? If not download one! It’s free in the resources section and will give you the test procedures for every thing in your truck.

 

[Brindleboxer]

Download the FSM and EWD from the resources, these are both great reference when working on our trucks. The FSM will give you procedures for troubleshooting. https://forum.ih8mud.com/resources/1993-1994-fzj-80-updated-and-combined-fsm.124/ and https://forum.ih8mud.com/resources/1994-fzj80-ewd.96/.

I wouldn't jump to any conclusions, check the plugs and then use that information to help with troubleshooting from the FSM. If you post here, people will chime in.

As for reading the codes, there are several threads but here is a good one for reference. How or where to read codes for a 1994 80 Series?? - https://forum.ih8mud.com/threads/how-or-where-to-read-codes-for-a-1994-80-series.470427/

 

[BILT4ME]

Don't assume this is the HG.

You've done the coolant test. PASSED
You've checked the oil and no milk: PASSED
Not losing coolant: PASSED
Spark Plugs: One was darker, were any looking brand new or steam-cleaned?

Do a compression test dry and wet to determine if two cylinders next to each other have a lower compression.

Have you taken it out on the highway and driven it like 20 miles at highway speeds? What's it look like then?

A true HG problem gets worse with time and as you drive, it does NOT get better. Frequently it gets worse.

Does the smoke smell like maple syrup?
Does the smoke smell like wet gasoline?

A fuel injector dumping gas into the cylinder will wash a cylinder and it will create white smoke.
Oil is blue smoke.
Coolant will create white smoke that smells like maple syrup.
Yellow-green smoke out the exhaust could be Freon being ingested into the engine and is now Mustard Gas. RUN AWAY! (Seriously)

If this truck has sat a lot, I would look at rodent wire damage on the wiring harness that has maybe grounded out one or two injectors and it it dumping fuel into the cylinders.

What was the temperature, dew point and relative humidity the day you took that picture?

Below is my truck on a normal "winter" morning. High humidity, cool temps, cold start. Did this for about 10-15 minutes.

 

[HuyFZJ80]

Sounds like I’ll be learning how to do a compression test soon. New tool day!
Highway driving is fine. After a couple minutes of driving, it does go away. I’ve been checking both the oil and coolant daily. Coolant level did drop about 2 inches in the reservoir, which is concerning/new.
Exhaust doesn’t smell like anything in particular, just standard exhaust smell. Not sweet like syrup. Pics in the first post were in the afternoon, temp around 60, so not cold outside, and low humidity.

 

[HuyFZJ80]

Couple more tests done to diagnose my issue.

Compression test results by cylinder:
1 - 175
2 - 165
3 - 168
4 - 160
5 - 145
6 - 170

Cylinder 5 has the lowest compression by far. The compression test for 5 with oil didn’t change anything.

Oil sample sent to Blackstone showed a very small amount of antifreeze in the oil. 0.32%. Their recommendation was that I can continue to drive it and keep an eye on my coolant levels, while changing the oil more frequently. This doesn’t sit too well with me though.

So what do you fellas think? Head gasket? Hopefully it’s not a cracked head/block. Best case, maybe the oil cooler?

 

[TheBussman]

pressurize the cooling system with a pressure tester and then put a camera in the spark plug hole look for coolant dripping in.


generally speaking head gaskets get worse the hotter/longer you drive. Cracks are worst at cold start and get better the longer you drive but there are always exceptions.

 

[Fj80oregon]

Good suggestion above, also pulling the valve cover with the coolant system pressurized can reveal any cracks in the head.