Hissing sound and smoke from engine after starting, then car dies

Could a blown head gasket put pressure in to the cooling system and cause the pressure relief to open? It couldn’t so fast. Seems like it would have to be something like an ice clogged exhaust.

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A lot of vehicles only use an O-ring (seal) for sealing over/instead of a gasket…


I wouldn’t call that round gasket in the photo above an “o-ring” myself. I think of an o-ring as being constructed more like a torus.

In any event, there are two potential gaskets involved w/a thermostat replacement job , one for the housing, and one for the thermostat itself. I suppose one gasket might be able to do both jobs. Is that what you mean by the gasket you show above?

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The thermostat seal is the seal for both the thermostat and the housing on my old Dodge, these have been around since the 1990’s.


Don’t over think it George, it is a square cut O-ring with a groove made into it for the T-stat to seal… A seal can be anything that used in the sealing of 2 parts, your refrigerator doors have seals around them…

Seal used as a verb: 4 of 5

b. : to close or make secure against access, leakage, or passage by a fastening or coating.

Not it might, it HAS been doing it for 20+ years…


So when I was going to replace the thermostat I noticed a small leak at the upper radiator hose where it connects to the housing directly above the thermostat housing.

I wiped it off but I’m not seeing the leak anymore. I wrapped towels around both points. Drove it for 10 minutes, let it idle, turned on heat. Towels were dry. No coolant on ground in usual spot. BUT noticed a small wet spot on ground outside under driver’s seat area, wtf.

Also when the engine was running the coolant reservoir was at hot full line. It is at cold line when cold. Dash temp gauge is still just below half-way. Coolant test showed in range. And still have some white smoke from tailpipe.

The engine no longer stalls? Is the weather above freezing? Maybe the muffler is full of water/ice. Listen to the exhaust for gurgling while the engine is running.

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Correct, no more stalling since I banged on the fuel pump. Forgot same thing happened February of 2022 and there was the same sound. Have video from then too.

Since this happened weather has been above freezing, up to 60 degrees during the day.

Banging on the tank, stuck fuel pump. Manipulating gear shift, interlock switch or brake pedal interlock if so equipped. Cars age, things wear out.


It’s possible that’s just water draining from the A/C evaporator drain. Since the A/C is used even in the winter in “defrost” mode, crossing fingers, may be normal. Could also just be the normal windshield drain path is draining to the ground after your park it, esp if this occurred soon after driving in the rain. Have you addressed the fuel pump symptoms yet? I’m guessing your car may need a general infrastructure upgrade to bring it back into reliable-runner status. I’ve had to do that on my truck once or twice over the years, replacing all of the cooling system’s rubber hoses, drive belts, vacuum & fuel lines. It’s easier to do everything at once rather than bit by bit. Consider to hire a shop for a “general inspection”. They’ll inspect it from every angle and tell you what work needs doing and in what priority.

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Water spots under driver area went away. This was the area.

Still looking for an honest, competent mechanic.

That looks like the flange at the catalytic converter?

You need a very good that specializes in exhaust repairs


I once had the same problem with my 2005 Buick Century. It died shortly after starting because the fuel pump was bad. The smoke and hissing you have may or may not be a separate issue.

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Modern cars just won’t run correctly unless the entire path from the intake to the tailpipe is air-tight. Suggest to focus on getting the exhaust system leak-free. Note that some water leaking from the end parts of the exhaust system (muffler, tailpipe, etc) may be normal as the engine warms up.

“Still looking for an honest, competent mechanic.”

The way to find a good mechanic is the same way you find a good physician, dentist, lawyer, etc. Ask your friends, relatives, co-worker for personal recommendations. Excepting dealership mechanics – who are usually well trained and carefully supervised – it is very difficult to find a good mechanic by confining your search to the yellow pages, newspapers, internet, yelp, etc.

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After replacing the exhaust system, you might still see water (condensation) drip from the exhaust joints, this is not an indication of failure.

What do you need to be repaired?

Those are more likely to be guys that recently “graduated” from UTI and are under TREMENDOUS pressure to get things done “yesterday”

I see the position of dealership more as a stepping-stone type of job

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… or possibly from Lincoln Tech.
When my HS counselees expressed a desire to become an auto mechanic, I used to steer them toward the excellent (free) program at the county vocational school. A few of these students opted instead to pay a HUGE amount of money to attend Lincoln Tech, and most of them later came back to visit me and to tell me that they had learned very little at Lincoln Tech, even though they had spent a lot of money.

Nashville Auto Diesel College (NADC) founded in 1919, used to be a great school, then it just started going down hill fast, I think there Diesel program is still pretty good, but the auto side of it is just too fast paced to do any good… I have worked with many many students from there and was never impressed, the only ones that got anything out of it were the ones already very mechanically inclined or had prior experience… Most of them think they know everything cause they passed a 2 weekish class on transmissions or brakes or whatever and they had a piece of paper… The brakes were on a wall in the class room, not on an old rusty worn out time welded car out in the shop… lol
Lincoln Tech bought them out years ago, don’t remember the time line if that is when they went down hill or not… Point is you can NOT send someone green through a 11 month school and expect them to be ready for the real world… Heck we had to tach everyone of them that had never worked in a shop before how to rack a vehicle or properly floor jack a vehicle, I mean for $24,000 I would damn sure hope they would teach you how to rack a car… :man_facepalming:

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We USED to have an excellent diesel mechanic school in this area. Then, they were bought-out by Lincoln Tech, and everything went to hell.



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