Engine noises
Thread Starter
1st Gear
Joined: Mar 2005
Posts: 1
Likes: 0
Engine noises
Hello everybody,
Im a newbe here. I just found this forum and it sounds like a great one.
My father just bought his first vet at 60 years old. He bought a 91 convert in show room condition with only 30,000 original miles, from his nephew.
We picked it up in Ogden, Utah last summer. On the way home to California we stopped in Wendover and the engine was making an awful rattleing noise. (really loud) We let it sit for a couple hours and it was still there. So, we put some STP treatment in it for the heck of it and it diddint do anything. We drove it on home with the noise, the further we drove the quieter it got.
We changed the oil when we got home, and still to this day it still makes the noise every now and then. Mostly when you give it a rev and let off. (When the idle is comming down we here it)
I have read through the threads and only found it to be the pre cats or loose rockers. But with my stethescope it sounds like the middle of the engine. No noise from the rocker covers , oil pan or the pre cats.
Has anybody had this problem or have any ideas on what it could be?
Thanks in advance........... Rob
Im a newbe here. I just found this forum and it sounds like a great one.
My father just bought his first vet at 60 years old. He bought a 91 convert in show room condition with only 30,000 original miles, from his nephew.
We picked it up in Ogden, Utah last summer. On the way home to California we stopped in Wendover and the engine was making an awful rattleing noise. (really loud) We let it sit for a couple hours and it was still there. So, we put some STP treatment in it for the heck of it and it diddint do anything. We drove it on home with the noise, the further we drove the quieter it got.
We changed the oil when we got home, and still to this day it still makes the noise every now and then. Mostly when you give it a rev and let off. (When the idle is comming down we here it)
I have read through the threads and only found it to be the pre cats or loose rockers. But with my stethescope it sounds like the middle of the engine. No noise from the rocker covers , oil pan or the pre cats.
Has anybody had this problem or have any ideas on what it could be?
Thanks in advance........... Rob
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by 502z28
Hello everybody,
Im a newbe here. I just found this forum and it sounds like a great one.
My father just bought his first vet at 60 years old. He bought a 91 convert in show room condition with only 30,000 original miles, from his nephew.
We picked it up in Ogden, Utah last summer. On the way home to California we stopped in Wendover and the engine was making an awful rattleing noise. (really loud) We let it sit for a couple hours and it was still there. So, we put some STP treatment in it for the heck of it and it diddint do anything. We drove it on home with the noise, the further we drove the quieter it got.
We changed the oil when we got home, and still to this day it still makes the noise every now and then. Mostly when you give it a rev and let off. (When the idle is comming down we here it)
I have read through the threads and only found it to be the pre cats or loose rockers. But with my stethescope it sounds like the middle of the engine. No noise from the rocker covers , oil pan or the pre cats.
Has anybody had this problem or have any ideas on what it could be?
Thanks in advance........... Rob
Im a newbe here. I just found this forum and it sounds like a great one.
My father just bought his first vet at 60 years old. He bought a 91 convert in show room condition with only 30,000 original miles, from his nephew.
We picked it up in Ogden, Utah last summer. On the way home to California we stopped in Wendover and the engine was making an awful rattleing noise. (really loud) We let it sit for a couple hours and it was still there. So, we put some STP treatment in it for the heck of it and it diddint do anything. We drove it on home with the noise, the further we drove the quieter it got.
We changed the oil when we got home, and still to this day it still makes the noise every now and then. Mostly when you give it a rev and let off. (When the idle is comming down we here it)
I have read through the threads and only found it to be the pre cats or loose rockers. But with my stethescope it sounds like the middle of the engine. No noise from the rocker covers , oil pan or the pre cats.
Has anybody had this problem or have any ideas on what it could be?
Thanks in advance........... Rob
Sure sounds like the cats to me. Raise the car up and then bang on the cat to see if any rattle can be heard from the cat. If it was a mechanical problem with the engine one would think it would have came apart by now
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by 502z28
On the way home to California we stopped in Wendover and the engine was making an awful rattleing noise. (really loud) We let it sit for a couple hours and it was still there.
It is almost impossible to diagnose a noise without hearing it. It could be anything from a rod knock to loose lug nuts. The, "it sounds like the middle of the engine.", points more to a rod knock, than anything else.
RACE ON!!!
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
If you had not said ..."Mostly when you give it a rev and let off. (When the idle is comming down we here it)" I would have suspected timing and pre-detonation (engine knock or pinging) . Is it happening under heavy load? or only when it is returning to idle?
If it is under heavy load, I would check the tiiming and ensure you use a higher octane gasoline.
If it is under heavy load, I would check the tiiming and ensure you use a higher octane gasoline.
