Originally more silent, after being opened up and the head gasket changed, the engine sounds like a muffled tractor - think race car, just not as loud; with the occasional added sound like an electric fan, of the pulleys running.
The car now also shakes/vibrates during acceleration at speeds above 90kph (56mph).
There was no change in the type of engine oil used.
My mechanic insists it’s normal, which doesn’t make sense. I would appreciate some advice on what the issue could be and possible solutions before meeting with a different mechanic.
It was troubleshooting to fix an overheating issue; having worked on the radiator, the fans and the heat sensor with no change. Turns out, it was the Electronic/Engine Controller Unit that needed reprogramming so the fans would run as required instead of for just about 20secs and then turning off.
The loud sounds started after the gasket change and before the ECU was fixed; and they are still active.
The likely culprit is an exhaust leak somewhere around the exhaust manifold. The exhaust manifold needs to be disconnected from the cylinder head when replacing the head gasket. They could have broken a bolt that attaches the manifold to the head or the manifold to the intermediate pipe. Was the head gasket replaced by a legitimate repair shop or ???
The flex pipe may be damaged or an exhaust donut broken. With no donut the manifold may have shifted or part of a flare might have blown away from rust. An exhaust shop will find the leak with or without the pointy stethoscope.
As I was reading, as for the noise, I was also thinking exhaust leak, for the reasons mentioned. To do the heads, the manifold comes off, and the pipes take more “jiggling” around than under normal operation.
As for that, I’m thinking about a motor/transmission mount that didn’t get torqued back correctly if any had to be loosened or removed to do the head. (IDK what it takes on that CRV).
As for that? Holy cow? No one should have touched your head gasket. This makes me think it’s not a particularly competent shop.
I question the wisdom of replacing the head gaskets in a nearly 30 year old Honda, myself.
Of course, a family member of mine is convinced his worn out, problematic 2002 Chevrolet truck just needs a new engine and transmission to make it “like new” again. Nevermind that everything else on the truck is 23 years old…
No CRV experience, knucklhead diy’er, but the symptrom sounds like a exhaust system leak. Either ask shop to try to find the location, or Google how to find exhaust system leaks.
It’s possible the catylitic converter has been stolen too.
My point was that the head gaskets didn’t have an issue. It was a simple issue of overheating because the fan controls weren’t working properly. That a huge FAIL in terms of diagnosis. Talk about making expensive guesses!
It sounds like the fan operation has been modified to cover up the high temperature problem. I don’t believe there is a need to change the computer programming after 28 years.
Ok then @Nevada_545. But if there was a head gasket problem leading to overheating and the head gasket was competently replaced, then why would the subsequent “diagnosis” have been an ECU problem about the fans. Sure, the OP called it “reprogramming” - but I don’t thing that the OP is talking in strict auto-tech-speak.
It doesn’t sound like it needed a head gasket.
Of course, that doesn’t address the OPs questions in either case.
With the limited information available, identifying the cause of the overheating won’t be possible. But if the engine was allowed to overheat, the head gasket could have been damaged.
Why is the vehicle noisy? Someone should listen to the vehicle to determine if there is an exhaust leak, rattles etc.
Why is there a vibration? Have flat spots developed in the tires while parked? Are the tires old? Is this an axle vibration? Someone needs to drive the vehicle and make this assessment.
The head gasket was reportedly replaced for “troubleshooting to fix an overheating issue.” That’s some crazy “troubleshooting” - esp if it “turns out” that it was an ECU fan control issue.
Concur. Absent other evidence , diy’er me would have replaced the radiator & cooling system pressure cap before considering the head gasket as the overheating cause. I sort of get the impression that not all of the pertinent information is being conveyed here.
I don’t think anyone said anything about the fans running continuously.
The info (obviously scanty) back up in post #3 was that the fans would only run for 20 secs rather than continuing as long as they needed to:
I get @Nevada_545’s skepticism about “reprogramming” - not likely either. But the best info we have is that the ECU was not running the fans correctly. Maybe it was replaced entirely.