Headgasket going out?
Thread Starter
Lead Lap
Joined: Nov 2002
Posts: 621
Likes: 1
From: ATL, Georgia
Headgasket going out?
Well I believe the headgasket on my 1997 LS400 is seeping. All the signs are there. The coolant temp. gauge is slightly fluctuating, the coolant level is slowly decreasing, and there's a white smoke coming out of the tailpipe when revving the motor. (that's when the motor has fully warmed up)
So what are my options? I'm thinking a used motor, if I can find a cheap low mileage 1UZ-FE. Or should I just replace the headgasket on my current 1UZ-FE and change out all the gaskets while I'm in there?
The car has not overheated, but I'm not sure how much longer the headgasket will stay together.
So what are my options? I'm thinking a used motor, if I can find a cheap low mileage 1UZ-FE. Or should I just replace the headgasket on my current 1UZ-FE and change out all the gaskets while I'm in there?
The car has not overheated, but I'm not sure how much longer the headgasket will stay together.
Rookie
Joined: Jul 2006
Posts: 53
Likes: 1
From: CA
My advice would be to have an oil analysis performed and / or a cylinder leakdown test done. Both are reasonably inexpensive and would probably provide the level of diagnosis you are looking for; they may also give some insight on the overall condition of the engine, at least from a relative standpoint.
Jeff
Jeff
compression test do it yourself it will cost around 70 for the test...., and check the oil like the others have said and also check the coolant .. good luck hope it isnt bhg
Thread Starter
Lead Lap
Joined: Nov 2002
Posts: 621
Likes: 1
From: ATL, Georgia
It doesn't seem as if the oil is mixing with the coolant at this point. I will likely get a compression test on the cylinders in the coming week.
And yes the coolant level has gone down slightly since I had the radiator replaced. New toyota red coolant was added and the level was right at the low level. After a month of driving the coolant level is noticeably below the low marker. And no, the radiator was not replaced because it overheated. The radiator just looked like it was going to go out, so I had it replaced.
I believe the car would be overheating by now, but the reason it isn't is because of the design of the cooling system. From what I understand the coolant reservior tank is mounted high in the engine bay, so that it will bubble air out naturally. My theory is that the cylinders are pulling coolant in and burning it off in the exhaust. Also air is getting into the cooling system, but is automatically bleed out.
And yes the coolant level has gone down slightly since I had the radiator replaced. New toyota red coolant was added and the level was right at the low level. After a month of driving the coolant level is noticeably below the low marker. And no, the radiator was not replaced because it overheated. The radiator just looked like it was going to go out, so I had it replaced.
I believe the car would be overheating by now, but the reason it isn't is because of the design of the cooling system. From what I understand the coolant reservior tank is mounted high in the engine bay, so that it will bubble air out naturally. My theory is that the cylinders are pulling coolant in and burning it off in the exhaust. Also air is getting into the cooling system, but is automatically bleed out.
how can you be sure that the white smoke isn't caused by a faulty PS idle up valve?
get a block test done, they sell the block testers at napa, they go into the coolant neck and look for combustion gases.
get a block test done, they sell the block testers at napa, they go into the coolant neck and look for combustion gases.
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Thread Starter
Lead Lap
Joined: Nov 2002
Posts: 621
Likes: 1
From: ATL, Georgia
I hope my overflow tank is leaking and it's not the headgasket... but the only thing that gets me is that the temp gauge is fluctuating. We'll see soon.
And yes I think it could be the PS idle up valve, but how would that be diagnosised?
And yes I think it could be the PS idle up valve, but how would that be diagnosised?
a blown head gasket with coolant dumping out of the exhaust would ruin ur 02 sensors,cause the check engine light to go on and dump fuel into the cylinders and wash them out, ur plugs would be saturated as well....its not a head gasket. especially if u didnt over heat it to an extreme
Driver
Joined: Dec 2007
Posts: 155
Likes: 0
From: Maryland/Florida
I have the exact same issues on my car; fluctuating temperature gauge, missing coolant, and slight smoke on startup. I doubt it's my headgasket though and suspect my cooling system needs a good rebuild, although the headgasket is still a possibility with this many miles on my car.
Fluctuating temp gauge would point to the thermostat and air pockets. Change the thermostat and get the air out.
If you had a blown head gasket your temperature gauge should generally shoot right up to boiling and stay there.
Your headgasket is not blown. These motors pretty much do not blow headgaskets unless they overheat. Slow leaking head gaskets are also not an issue, these motors have aluminum head and block, theres no corrosion.
You water pump is most likely leaking, therefore your temp fluctuates and coolant is disappearing. Give it a couple more weeks and it will start overheating.
The white smoke from the exhaust is probably just moisture, which is normal, or maybe your power steering air valves is leaking.
Get your water pump replaced, and don't worry about the head gasket.
You water pump is most likely leaking, therefore your temp fluctuates and coolant is disappearing. Give it a couple more weeks and it will start overheating.
The white smoke from the exhaust is probably just moisture, which is normal, or maybe your power steering air valves is leaking.
Get your water pump replaced, and don't worry about the head gasket.
Agree with the previous. If the car doesn't have chocolate milk looking oil, the loss of coolant is elsewhere, not a head gasket. Reservoir cap, water pump, radiator hose or thermostat housing leak...
Thread Starter
Lead Lap
Joined: Nov 2002
Posts: 621
Likes: 1
From: ATL, Georgia
Originally Posted by Och
You water pump is most likely leaking, therefore your temp fluctuates and coolant is disappearing. Give it a couple more weeks and it will start overheating.
I will definitely check out what's going on with it and get back to you guys. I'm glad to hear that this motor is not prone to headgasket issues. I didn't think it was, that's among the reasons why I bought it.