Engine knock!!!!

[Matman98]

Well.....The Sea Dragon is in the shop. Had to take her in due to a knock in the engine. Service guy stated that the last SSR that was in for that noise had to have the engine replaced. Thank GOD for the GMPP insurance. I hope that she will be alright. Anybody else had this happen to them? Is there a flaw in the engine or something? Any info would be greatly appreciated.

Thanks,
Matman98
"The Sea Dragon"

[wildcat66]

don't recall, hearing to many complain about engine issues, I hope you get it fixed and back out crusing soon. did you try a search on here?

[Greg Ducato]

It might still be somthing minor like a cracked flywheel or loose converter bolts. How many miles do you have on your truck?

[Matman98]

Well athe service department called and.....GOOD news, My baby will be out of the shop this evening!!!!! They said it was the catalitic converter....Thank GOD!!!!! Now the bill......bummer.... The truck only has 30500 miles on her.......This is a great website!!!! Thanks guys and gals for the input....

[BlueStreak]

Originally Posted by Matman98

Well athe service department called and.....GOOD news, My baby will be out of the shop this evening!!!!! They said it was the catalitic converter....Thank GOD!!!!! Now the bill......bummer.... The truck only has 30500 miles on her.......This is a great website!!!! Thanks guys and gals for the input....

At that mileage the catalitic converter should be covered by warranty on the emissions controls.

[MnMsToy]

I did not know that a catalitic converter would/could knock? Anyone have a sound clip?

[Doug Allen]

Originally Posted by BlueStreak

At that mileage the catalitic converter should be covered by warranty on the emissions controls.

[Greg Ducato]

Originally Posted by whatfor90

I did not know that a catalitic converter would/could knock? Anyone have a sound clip?

The internal catalyst , the "honeycomb" part, can get loose inside the metal housing of the converter. As the converter heats up, the exhaust pulses will rattle the catalyst and produce a knock that is akin to the sound of a plastic screw driver handle rapped against a steel tube. It is usually more noticeable in the garage or at a drive thru where the sound will be reflected back to the vehicle.

[gabe74gt]

i think your truck is out of engine oil. or may be some water splinted into it. better is to get that checked at first

[ssr71]

Originally Posted by BlueStreak

At that mileage the catalitic converter should be covered by warranty on the emissions controls.

Originally Posted by Doug Allen

Emissions controls are covered for 8 years or 80,000 miles under federal law - regardless of any factory warranty. That includes nearly all sensors as long as they are emissions related - MAF, MAP, O2, evap system, etc.

[Matman98]

Greg has it pretty well on the nose. FYI Gabe74GT, I checked all the easy stuff. The Sea Dragon doesn't use any oil and dosen't overheat so it was either in the engine, a rod or lifter or whatever, so in to the shop under warrenty to alliviate the problem. ssr71 also has it right, it is covered completely under the emissions warrenty. They replaced both Converters and did a complete checkup as well. They even washed and buffed her out because they took a day longer than expected. She looks good.....runs quieter and smooter now also. Thanks all for the input, youare all great.....

[Tom Savini]

Good for you love it when a plan comes together. It's the weekend get out there and enjoy that beauty.

Tom

[faithofgod]

I wonder if that is what mine has. She only has 31,000 miles and has a sporadic almost knocking sound (not like normal engine knocking). I thought about recording it with the Blackberry and posting a link here in case anyone knows. The catalytic converter would be much better than an engine problem :-)

[wingrider]

I just replaces my converters about a month ago for this same problem, sounds just like a rod knock.

[abadssr]

sure hope they keep a stock of these around

[wingrider]

at the time i ordered mine they had plenty in stock in Lansing, I had mine in two days.

[MnMsToy]

Does it really sound like a rod knock

[HarleyGuy]

Is this a common issue with these converters an do we know who the manufacturer is?
Of all the vehicles that I've owned, I've never had to replace a converter and at 30,000 miles it would seem to me that there must be some type of defect.

[DOOPHUS]

Originally Posted by HarleyGuy

Is this a common issue with these converters an do we know who the manufacturer is?
Of all the vehicles that I've owned, I've never had to replace a converter and at 30,000 miles it would seem to me that there must be some type of defect.

Good point, HarleyGuy.

The only converter I've ever had to replace was on the Jeep but it was about 15 years old at the time.

[xoxoxoBruce]

Originally Posted by abadssr

sure hope they keep a stock of these around

Since it's part of the federal emissions system, and therefore under the emissions warranty, they probably will.

[MnMsToy]

Originally Posted by DOOPHUS

Good point, HarleyGuy.

The only converter I've ever had to replace was on the Jeep but it was about 15 years old at the time.

I had to replace one on a Masda Miata with only 21,500 miles but the knock did not sound like a rod knock.

[abonadies]

I have an 05 ssr with 19k on it and it has a odd knock sound only when its cold,first started goes away at about 180 degrees temp ????? Whats the best way to check if its the cats causing the noise ????

Thanks Art

[abonadies]

bump

[FUZZY]

Originally Posted by abonadies

I have an 05 ssr with 19k on it and it has a odd knock sound only when its cold,first started goes away at about 180 degrees temp ????? Whats the best way to check if its the cats causing the noise ????

Thanks Art

Art

Your description doesn't sound like the cat noise. What you're describing is a similar "normal start up symptom" of the GM small block of today. The motors are produce with a specific tollerance (believe it is .005) between the pistons and piston walls. When the engine warms up the tollerance drops to between .0025 and .003 which is when the noise disappears.

The noise you hear has been noted in GM rcords as being " Piston slap on cold start up" According to GM there is nothing they can do about it. Or that they want to do about it

Hope thios helps you to understand your noises.

[Topspin]

Just hitting the converter with a rubber mallet will usually give you your answer. Itwill certainly rattle if it's the culprit. Sometimes a lifter will bleed down at rest and take a short period of time to pump up and quiet down. It sounds like more of a piston clearance issue, like Fuzzy stated, because of the amount of time it takes to quiet. They actually went to coated piston skirts in the LS2 engine to supposedly cure that issue. Keep a close ear on it, because if it continues to get louder real damage might occur.

[Tom Savini]

Originally Posted by Topspin

Just hitting the converter with a rubber mallet will usually give you your answer. Itwill certainly rattle if it's the culprit. Sometimes a lifter will bleed down at rest and take a short period of time to pump up and quiet down. It sounds like more of a piston clearance issue, like Fuzzy stated, because of the amount of time it takes to quiet. They actually went to coated piston skirts in the LS2 engine to supposedly cure that issue. Keep a close ear on it, because if it continues to get louder real damage might occur.

Your right about the difference between the LS1 that my wife has in her 2001 Trans Am being louder that the LS2 in my SSR. Hers sounds real loud cold and quiets down after a few minutes. It scared her the first cold (for Texas ) day we had.

[rogerdoger]

this is such a great site im sure glad i found it and became a member the tech advice is 2nd to none

[Topspin]

Hey rogerdoger, I'm real curious as to what your removable luggage rack looks like? Do you have any pictures you could post?

[cwmorgan]

At 97,600 miles, the engine light came on for the first time ever. The Chevy dealer reported the problem to be the catalytic converter. The replacement cost exceeds $1,600 of which less than $200 is for labor, and it will require three days because the parts must be ordered from elsewhere. :-(