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Hey everyone so i joined this forum looking for some help on my 2010 nissan skyline 250gt..so the the day i bought it after awhile of driving i noticed coolant leaking..with further inspection it was leaking around the thermostat area out of a small hole…i started to overheat and a check engine light came on trying to make it back home..after two days the leaking suddenly stopped(coolant was always full) but still over heating..i went to a mechanic and they found that my thermostat was stuck and cut the spring out so its always open(i live in a warm climate) after testing the vehicle it still overheat but this time the right intake is significantly louder that the left and radiator hose is rock hard to the touch while the reservoir is boiling over and the car is also misfiring..is that a sign the head gasket is bad or somethings else

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After modifying the thermostat which we thought caused the overheating they settled on it being the head gasket..because its stutering/misfiring and overheating and the right side intake would get very loud after it got hot…but it never use to stutter before modifying the thermostat..just wanna see if theres any other diagnostic 

Edited by Kesh20

It is very likely that the car already had a blown head gasket when you bought it, which is why the previous owner sold it. 

The symptoms you describe very much sound like a blown head gasket. The mechanic saying it's a blown head gasket sounds like it has a blown head gasket. 

If I had to guess I'd also say it has a blown head gasket. 

  • Haha 3

Well its definitely the headgasket(hopefully not hopefully) but its not mixing anything.. the oil and coolant are fine..its just the combustion gasses getting into the cooling system causing it to be very pressurized with hot air..so yeah..headgasket fix in the future…what i do want to know is if a bad head gasket can cause a car to misfires 

2 hours ago, Kesh20 said:

what i do want to know is if a bad head gasket can cause a car to misfires

Yes it can.

2 hours ago, FiXtUrE said:

The above would not cause misfiring issues though, start with checking the timing, spark plugs, coils also.

He is wrong. He knows nothing about this stuff, so better not listen too hard.

I still think that he is a GPT3/4 chatbot.

  • Like 2

Head gaskets can fail and allow combustion gas and coolant to mix. Or combustion gas and Oil, I suppose.

It's not only water and oil.

Your engine being fed a constant stream of coolant into its combustion chamber can absolutely cause a misfire. Infact that is how I know I cracked my block multiple times because the coolant channel on a RB is closest to the chamber. It would misfire at idle (water going into cylinder), then not misfire when cylinder pressure exceeded the coolant pressure. (combustion pressure pushing into coolant system).

You could check this by looking for residue in your radiator. But as mentioned, Someone who has physically seen the car has looked into it already and thinks it's a head gasket. The giveaway is the fact all of these problems seem to be on .. one side?

Yes this is a VQ, but a gasket fail can happen in any combination. It depends on what things are combining that are best left seperate. It could be multiple things, but all of these "things" outside the engine internals are

a) Radiator
b) Thermostat (the engine will not overheat by the way if stuck OPEN)

Anything else and you're pulling the motor apart to find/fix.

30 minutes ago, FiXtUrE said:

Explain it then, why is it misfiring then gtsboy, instead of cut and pasting bullshit from similar threads.

There's more than one way that a combustion chamber to coolant system head gasket failure can cause a misfire. It can let a lot of water into the chamber during the induction stroke, quenching the ignition event. It can cause a lot of compression to escape the cylinder during the ignition stroke, causing a really soft ignition even that feels like a misfire, even if it is technically not. And there's others.

Here's the thing. Anyone can work this out for themselves, just by thinking about what goes on inside the engine.

31 minutes ago, FiXtUrE said:

can I ask what gtp3/4 I means?

ChatGPT (at version 3) is an AI (Well, actually, the use of the term AI is highly misleading, but let's let the people who created it think that they have created AI) natural language processing model that can handle queries addressed to it in "natural language" (ie, as typed in, or perhaps spoken, by your normal level of ~100IQ citizen/pleb) asking such things as "how do I remove the buttplug if it feels like it is stuck?". You know, the sort of thing that you get on reddit and other dubiously useful places. The model pulls apart the sentence and  tries to work out what it means. It is almost 100% based on statistical likelihoods that result from training on simply massive databases of language content, trained into neural nets or other associative models. There is no real understanding. The frightening thing is that the models are actually able to determine the meaning of the query or statement a lot of the time. Then, the model can try to provide an answer. They do this by performing web/google/database searches using search terms associated with the original query, drag together the results and summarise them into a seemingly concise answer. Often right, often really badly wrong, sometimes in very subtle ways.

We had a new user sign up here recently, start dredging up old threads on useless topics, and posting replies that were clearly only half understood and could have been regurgitated from the usual sources of bad advice, such as reddit, etc. I called it out as a very likely chatbot, the admins appear to have dealt with it and it hasn't been seen since.

ChatGPT4 is supposedly even more sophisticated. Released very recently. Supposedly the AI behind the new Bing assistant thing that they're trialling (with hilarious results).

The way that you respond in threads has all the hallmarks of a chatbot. At least, whenever there is technical content anyway. It looks like you read the thread (in the same fashion as the chatbots do), do a search (in the same fashion that the chatbots do) and regurgitate incorrect content into the thread (just as the chatbots do). Even your posts on body kit pieces look just like it. A chatbot put to work by Aliexpress to drive traffic to the site would produce content that looks just like your posts in those threads.

It is only in cases like this thread, where it would be wholely unexpected for an actual chatbot to feign ignorance of the existence of ChatGPT, where you show a glimmer of human.

3 hours ago, Kesh20 said:

the oil and coolant are fine..its just the combustion gasses getting into the cooling system causing it to be very pressurized with hot air..so yeah

A head gasket failure doesn't always present in the same way.  A gasket failure between the oil gallery and the coolant will cause the oil to go a milky colour, but generally won't cause a misfire.

A failure between a cylinder and the coolant will cause a misfire and will pressurise the coolant system causing it to push the coolant out into the overflow tank and eventually overheat the engine.  A test of the coolant for combustion gasses can diagnose this issue.  From your description, this could be the problem.

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