White Smoke - Do I really want the answer? (1 Viewer)

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FJ40Savvy

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Apr 17, 2021
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Location
Calgary, Alberta
I when started Louie to relocate it for winter storage there was a large amount of white smoke coming from the exhaust. It was first time I have seen white smoke on start-up. The ambient temperature was about 2 degrees C (35 deg F). It didn't start well, I might have flooded it and once it started it ran very rough. Also concerning was seeing a small puddle of coolant on the floor (size of a quarter) once it was moved. I didn't see any leaks from hoses when I had a quick look under the hood. There was coolant on the lower front side of the engine that dripped on the front differential.

It is a stock 1973 F -Engine and as far as I know it has never been rebuilt. Odometer shows 7196 miles so I going to assume that it has wrapped once but maybe not. It might be a very low mileage FJ40 on the original sheet metal all around except for the front drivers fender. It was replaced due to a dent vs rust. I have driven Louie about 300 miles this summer and never noticed coolant on the floor when is was parked or white smoke on start up. The coolant level was steady all summer.

I have been reading other posts and they all seem to point to a head gasket issue. Over the winter I will do a compression test and maybe a pressure test.

Could the cold start up revealed an issue with the head gasket or worse crack in the block? Thoughts and ideas would be appreciated.
 
Like you said, do a compression test, or better yet a leak down test.
I managed to find a coolant pressure tester that I can borrow. Based on my reading, an OEM radiator cap is set to relieve pressure at 13 psi. Would I complete the leak down test slightly below this pressure?
 
Coolant in the combustion chamber is historic for white smoke. Head gasket ?
That is what i'm worried about. Tests should give me an idea of what is happening. The questions is why now? It ran great all summer and the last start up the white smoke appeared. Did the low ambient temperature highlight the issue which was really there all along?
 
That is what i'm worried about. Tests should give me an idea of what is happening. The questions is why now? It ran great all summer and the last start up the white smoke appeared. Did the low ambient temperature highlight the issue which was really there all along?

I do not believe there is one answer for when and why things fail. You have a 1973 and , maybe, it is original. Maybe it was replaced at some time as well. Either way , gaskets fail all the time. I have a 1969 and I have seen many dry up and crack / fail , etc.. And Murphys law always wins. If it is a Head gasket, after exchange you will have a lot of confidence.
 
I do not believe there is one answer for when and why things fail. You have a 1973 and , maybe, it is original. Maybe it was replaced at some time as well. Either way , gaskets fail all the time. I have a 1969 and I have seen many dry up and crack / fail , etc.. And Murphys law always wins. If it is a Head gasket, after exchange you will have a lot of confidence.
I guess the tests will tell and likely be doing a head gasket.
 
Did the white smoke smell sweet? A/F has a sweet smell when burning off. It could be just burnning off condesation, especially in colder temps. If the cylders and exhaust are so saturated with fuel it will steam. The fuel won't fire because the plugs are so wet and cant spark. You may have flooded it while trying to starting it. It would take a bit to clear the plugs and cylders and this will cause it to run rough for a while. When you pressure test the cooling system, apply around 13 to 15 psi. Let sit for about 10 or 15 min and see if it drops. If it does drop, you need to search all connections and systems for leaks. Is there water in the oil, are there bubbles in the rad when it s running? You really should do a dry and wet compression test 1st. If there are inconsistencies then some sort of cylndr leak down test is in order. Proper testing will set the direction for repair.
 
Did the white smoke smell sweet? A/F has a sweet smell when burning off. It could be just burnning off condesation, especially in colder temps. If the cylders and exhaust are so saturated with fuel it will steam. The fuel won't fire because the plugs are so wet and cant spark. You may have flooded it while trying to starting it. It would take a bit to clear the plugs and cylders and this will cause it to run rough for a while. When you pressure test the cooling system, apply around 13 to 15 psi. Let sit for about 10 or 15 min and see if it drops. If it does drop, you need to search all connections and systems for leaks. Is there water in the oil, are there bubbles in the rad when it s running? You really should do a dry and wet compression test 1st. If there are inconsistencies then some sort of cylndr leak down test is in order. Proper testing will set the direction for repair.
Thank you. It was definitely flooded, the garage smelled like gas. I will start with a cooling system pressure test to try and find out where the coolant leak is coming from and then do a compression test. Updates to follow
 
I have done lots of reading on this forum and I read somewhere "Prepare for the Worst, Hope for the best". Here is the update... I restarted Louie following the owner's manual starting procedure. It started with no smoke. Yay!!! In hindsight, I really flooded it.
Owner Manual Start.jpg


However there was still a coolant leak. I used the tool loan program at Canadian Tire and picked up a coolant tester. For those north of the border, CT loans tools for a deposit and provides a full refund of the deposit when you return the tool. Sweat deal for tools that you only use once in a while. As it turns out, one of the hoses attached to the thermostat housing was leaking. I'm not sure why it started to leak all of a sudden. I tightened the clamp and the system held pressure for 4 hours.

Coolant_1.jpg
Coolant_2.jpg


Good news ending for sure. I was really wasn't ready to off the head to repair a head gasket. I need more time learning from the forum before I attempt that. I will probably do a compression test for interest prior to the driving season next year. Thanks for all the input.
 

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