Chazzman17 Posted August 10, 2011 Report Share Posted August 10, 2011 This is my first post on this site, so please forgive me if this thread is in the wrong section. I own a 1998 Olds Intrigue with a series 2 3800. The engine has a knocking sound, but only once it reaches operating temperature. When cold, it sounds perfect. I have pulled the oil pan to check the rod bearings for play, but they are all tight, no play or slop at all. I did not see any metal shavings in the old oil or in the pan. Does anyone have any suggestions on what it may be or what to check next? I read somewhere that the flexplate may cause this. Is that possible? Any suggestions or ideas are much appreciated. Thank you! Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted August 10, 2011 Report Share Posted August 10, 2011 Maybe the innards of the cat rattling? Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted August 11, 2011 Report Share Posted August 11, 2011 Sure it isn't a bad water pump? I know it sounds crazy, but I had that issue with a Buick V-6 once. The pump never leaked, but made a noise that sounded EXACTLY like a bad rod bearing... Might be worth getting it to operating temp, then take the serpentine belt off, and run it BRIEFLY == don't want to overheat it, just see if the noise goes away... Quote Link to comment Share on other sites More sharing options...
regalman Posted August 23, 2011 Report Share Posted August 23, 2011 check the harmonic balancer,they go bad and sound like a rod knock. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted August 23, 2011 Author Report Share Posted August 23, 2011 Thanks for all the replies, soon as I get some time I will let you all know what I find out. Quote Link to comment Share on other sites More sharing options...
AL Posted August 25, 2011 Report Share Posted August 25, 2011 I am keeping a very close eye on this thread, I have the same issue Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted August 25, 2011 Author Report Share Posted August 25, 2011 Will be getting started on fixing my car this weekend. Gonna try your suggestions, and if it still knocks. Gonna pull the motor. Seeings it will be much easier to work on that way anyway. Have to also put a power steering pump and power steering pressure line on the car. The biggest mistake they made on the series 2 was putting the power steering pump in the back of the engine. Series one had it right where it should be. On top. Will do my best to keep you all posted this weekend. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted August 29, 2011 Author Report Share Posted August 29, 2011 So far this is where we are at my car. First thing the rod bearings I was told were inspected, could not have been inspected. 1st clue, the a/c compressor was never pulled. #2 clue, nor was the passenger side motor mount. The nuts and bolts were completed covered in road grime still. There is more to the story as well. But anyway, pulled the belt off as suggested and the car still knocks. Harmonic balancer seems to be fine, nice and tight with zero play. (unsure of how to check this for sure). S0 decided it was time to pull the oil pan and inspect the rod bearings, for certain this time. Definitely some tear down involved just to get the pan out. Finally got the pan out, did find a few small metal shavings stuck in the oil pick up screen. Could not really get any up and down play on the rod bearings, but #3 and #4 had more side to side play than #1 and #2. But #5 and #6 had quite a bit of side to side play, so much you could actually make them sound like a knock. So far have replaced #1 through #5. No spun bearings and no scoring anywhere, looks to be pretty normal wear. When #4 came off, right away we could smell what seemed like a burnt metal smell, though it looked ok. Will be doing the final #6 bearing tonight. Ran out of time last night to finish them all. But so far, after replacing the 5 bearings, the side to side play is now very minimal, if any at all. Which gives me some confidence. Especially with the #5. Well that's the update as of now, will continue to keep you posted. Thanks again for all the info and suggestions. Quote Link to comment Share on other sites More sharing options...
AL Posted August 30, 2011 Report Share Posted August 30, 2011 Is this your sound? Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted August 30, 2011 Author Report Share Posted August 30, 2011 Was just a still image, no sound Quote Link to comment Share on other sites More sharing options...
AL Posted August 30, 2011 Report Share Posted August 30, 2011 Try this http://s1239.photobucket.com/albums/ff510/bigalwalker/99%20Grand%20Prix%20GTP/?action=view¤t=video-2011-08-28-15-19-40.mp4 Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted August 30, 2011 Author Report Share Posted August 30, 2011 No, it is not near as severe as that. Wish I would of recorded the sound, to late now the car is tore down. The engine sounded perfect when it was cold. Soon as the engine started reaching operating temp, the knock would slowly get louder. The knock sound sounds similar to mine, but mine was a slow paced one. Not that rapid. Figured could indicate maybe just one rod is knocking. Also was informed it makes sense that when the car is cold the oil is thicker and taking up the gap in the rod bearings, so once it heated up and thinned out. It was able to start knocking again. Quote Link to comment Share on other sites More sharing options...
Galaxie500XL Posted August 31, 2011 Report Share Posted August 31, 2011 Check the timing chain...seen this before, the chain stretches when hot, leading to some interesting valve timing. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted September 3, 2011 Author Report Share Posted September 3, 2011 Update, finally was able to get back to work on the car. Pulled #6 rod bearing cap. Wouldn't you know it, the last one was in fact the culprit! Spun rod bearing #6. The bearing itself is pretty scarred up, but thankfully the crank had no scoring that you could feel. You could tell that on the crank the bearing had spun, but it did not dig into it. I plastigauged it with a standard size bearing, and was still within specs. One thing I noticed on #5 and #6 bearing cap was some really bad factory machining. Instead of being nice and flat and smooth on the tops where there attach to the rod, they were rough and jagged. The bottom of the rod was the same way. They fit back together perfectly, like that had been broken apart instead of cut. But definately a major flaw in the manufacturing. Gonna throw it all back together, hope the best. If it still knocks, just gonna swap the motor. I attached two images, one of the top of the bearing cap, the other the inside of the bearing. Thanks again for all the help, this is a great forum. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted September 5, 2011 Author Report Share Posted September 5, 2011 Well shes all buttoned up and on the road again, as of now no engine knock at operating temp. Keeping my fingers crossed she holds together. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted September 5, 2011 Report Share Posted September 5, 2011 Good work dude! I've heard of a few people changing rod bearings with the engine in-situ, and not having any adverse effects from it. Then again, I've seen people claim it doesn't last for shit...good work, and keep us updated! Quote Link to comment Share on other sites More sharing options...
AL Posted September 5, 2011 Report Share Posted September 5, 2011 Yah. I am very curious about the longetivity of this Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted September 6, 2011 Author Report Share Posted September 6, 2011 I am very curious about the long term of this as well. But figured since the engine only has around 80k on it and it was only 25 bucks for rod bearings, would try it before replacing the motor. Keeping my fingers crossed she lasts and holds together. Quote Link to comment Share on other sites More sharing options...
55trucker Posted September 7, 2011 Report Share Posted September 7, 2011 Curious. What was the cause for the spinning of the bearing in the 1st place? They usually do so because of lack of oil pressure which causes heat between the bearing & the journal. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted September 7, 2011 Author Report Share Posted September 7, 2011 I am not completely sure of the cause. The only thing I can maybe relate to the cause is the engine getting hot. I bought this car with several issues, hoping to fix it up. The radiator had a crack in it, and who knows how long the idiots who owned it before me drove it with the engine getting super hot. Thinning the oil out so much the journal just wasn't lubed properly. That's really all I can possibly relate it to. The previous owners did not take care of this car, whatsoever. From mechanically, to cleanliness. Definitely was/is a project car. But I look forward to getting her back to her full potential. Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted September 15, 2011 Author Report Share Posted September 15, 2011 Well I am at the 500 mile break in point and (keeping fingers crossed) all is still good! Changing the oil this weekend. Will continue to keep you all updated. Have a good weekend all! Quote Link to comment Share on other sites More sharing options...
sseiya Posted November 11, 2011 Report Share Posted November 11, 2011 did you swap out the bearings with the crank still in the car? Quote Link to comment Share on other sites More sharing options...
Chazzman17 Posted November 14, 2011 Author Report Share Posted November 14, 2011 yes I did, pulled to oil, popped the caps and swapped the bearing. Of course on the W-Body theres plenty to do before you can actually get the pan off, unlike the H body where you can just drop the pan. Quote Link to comment Share on other sites More sharing options...
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