Light smoke coming out of the hood while driving possible head gasket issue?

Tiny
NAED61
  • MEMBER
  • 2004 HONDA ACCORD
  • 3.0L
  • V6
  • 2WD
  • AUTOMATIC
  • 189,000 MILES
I had barely been driving any miles for the past 1+ year- sometimes once per 2-3 weeks. The car might sit for a week or more without being touched. 3 months ago, the battery began to fail- it took several attempts to turn over when cold. Then I noticed light smoke coming out of the hood while driving (and a few minutes after turning off) even though the engine temperature was perfect, and the engine was running fine. The battery was getting worse, so I took it to my mech. I told him about the starting problem but forgot to tell him about the smoke. I also told him how rarely I drive. He replaced the battery and told me that the car sitting drained the battery. He also told me I must drive at least 10 miles per week and run it at least twice per week. He also said he noticed the hood smoke, which he said meant I would need a new head gasket. I left, and immediately began driving at least 15-20 miles/week and drive at least twice/week never letting the car sit for more than 3 days. The smoke problem disappeared almost right away after starting this routine. It's been 3 months with no more smoke problem. Today I checked the inside of the oil cap- no residue of any kind. I removed the radiator cap and started the car- no bubbles at all, just perfect. Zero oil and coolant loss, no visible leaks. No warning lights and the engine just hums along perfectly and quietly. Order less Exhaust vapor when it's cold, which disappears after 2-3 miles. Compression feels great, power and acceleration are great. Do you think it's possible my mechanic mis-diagnosed the problem as head gasket based only on the smoke in the engine compartment? It was very busy that day- he was just finishing the new battery and clamp when I arrived. Thank you.
Sunday, December 31st, 2023 AT 3:45 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

I have no idea how he would diagnose the head gasket as bad based on what you described. To make that determination, the things you mentioned need to be checked. For example, engine oil contamination, thick white smoke from the exhaust, bubbles in the coolant, or checking engine compression to name a few.

I guess what I'm saying is I feel he likely misdiagnosed the problem based on a little smoke that may have come from anything. If it would make you more comfortable, take a look through this link. It explains what to check and the common symptoms of a failing head gasket.

https://www.2carpros.com/articles/head-gasket-blown-test

Let me know your thoughts and questions. However, it sounds like everything is fine as far as the gasket is concerned.

Take care and Happy New Year.

Joe

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Sunday, December 31st, 2023 AT 6:26 PM
Tiny
NAED61
  • MEMBER
  • 6 POSTS
Thanks Joe. I've been thinking the vapor rising from the passenger side of the hood might have been due to some coolant escaping from a clamped end of a hose (located near the head gasket area) which had become brittle due to inactivity. Once I started regular driving, the hose became supple again, and the seal closed off, ending the problem. Is this rational?
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Monday, January 1st, 2024 AT 10:23 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

It is very possible. Just keep an eye on the coolant levels for a bit to make sure there is no change. Also, if it is running good, I wouldn't be worried at all as far as driving it.

Let me know if anything changes or if you have questions.

Take care,

Joe
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Monday, January 1st, 2024 AT 6:24 PM

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