Arash Posted June 12, 2005 Report Share Posted June 12, 2005 Dear all members A few days ago my engine developed a strange ticking noise under throttle. Now the noise is very loud and harsh and occasionally comes at the idle too. It seems that it's coming from the middle of the engine and is very noticeable while driving. I've checked all the accessory area around the serpentine belt (recently changed) as well as the water pump belt and they are all ok. The noise is not a pulley noise or something like that. It's not continuous and is very loud. I have no clue how to diagnose this problem. Thanks in advance for suggestions. Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 How is the idle? Is the engine rough at all? Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 when you start the car you hear 3 or 4 loud ticks. Then you hear one loud tick every 7 or 6 seconds. Other than this the negine idles ok and the rpm remains at 500-600. There is no other noise. Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 Try changing the oil, add MMO and drive the hell out of it, no WOT's just a long highway drive. If you are lucky you have a sticking lifter. This IS a tick not a knock right? Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 What is MMO? this was initially a ticking noise but is turning in to a knocking noise and is getting louder. I'm afraid to drive the car anymore because today it got considerably worse. I assume you can repair a sticking valve lifter without taking the engine out. Am I right? How does adding MMO help? Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 Hmm a knocking noise is different especially if it has gotten worse as you observed. If it was a lifter, ticking, it may have been possible to clean it out with MMO (Marvel Mystery Oil) which I have found to be good cleaning the valve train. But it sounds like its more serious than a tick. So are you saying that it knocks every 6 or 7 seconds at idle? Does the knocks frequency speed up when you race the engine in park? Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 yes, as you increase the rpm the frequency of the knock increases. Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 I was just searching the FAQ section of this site for possible reasons for engine knock and main drive pulley was one of the possible causes. I just bypassed the AC compressor with a 73.4inch belt which was extremely tight and almost impossible to install. Can a very tight belt damage the main drive pulley and cause this type of knock? This noise started one day after I installed this belt. Link to comment Share on other sites More sharing options...
DFBonnett Posted June 12, 2005 Report Share Posted June 12, 2005 I think your next step would be to remove that very tight belt and turn everything it operates by hand. Possibly the tight belt damaged a bearing in the alternator or power steering pump. Worth a shot. Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 I was just searching the FAQ section of this site for possible reasons for engine knock and main drive pulley was one of the possible causes. I just bypassed the AC compressor with a 73.4inch belt which was extremely tight and almost impossible to install. Can a very tight belt damage the main drive pulley and cause this type of knock? This noise started one day after I installed this belt. Yes I forgot that you did that. If I am not mistaken you went even smaller than the belt I mentioned. I said to go larger than the belt I mentioned as the belt I mentioned was too tight. YES of course, get rid of that belt ASAP! Mike Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 Arash, this is the history of our discussion: I said this: If you want to quickly diagnose your noise buy a shorter belt (6K739 or a tad longer) and eliminate the AC Compressor from the serpentine belt circuit. This is a 73.9 inch belt If at all possible go to the NEXT available size this was a bit tight to get on... ****************************************************** You said this: Today I installed the belt (73.4 inches) with my brother; It was a little bit though as I had to pull the belt tensioner all the way back and there was not much space to work with. The car feels much more smooth and the harsh noise is totally gone. You were right on target on this one scotty. It was absolutely tight. We almost gave up on that. The belt's brand is Dayco and the part number is 5060735. I beleive It was made in USA and I paind $46.70 CAD for that. ********************************************************** At www.dayco.com The NEXT size up is 5060740, NOT 5060735. As a matter of fact, when I put in k060739 and ask for the interchangable belt at WWW.DAYCO.COM they come back with 5060740. I was shocked that you were able to get a 73.4 inch belt on as the one I tried to get on at 73.9 was REALLY TIGHT, AND my tensioner was opened up as far as it would go to the stop... SO that is why I suggested going to the next size larger. I DO hope you didnt do any damage to any accessories.. Mike Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 Today I try to release the belt tensioner a little bit to see if it solves the problem. I'm also going to check the accessories by hand and will post back Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 Hopefully you just burned out an idler wheel or the tensioner wheel bearing,.. As soon as possible get the longer belt to allow the tensioner to float its not good for it to be jammed up against the stop... Good Luck Arash, Mike Link to comment Share on other sites More sharing options...
Arash Posted June 12, 2005 Author Report Share Posted June 12, 2005 I just started the car and released the tensioner with the special arm and the noise was the same. Then I turned the car off,opened the belt, and cheched power teering pulley, alternator pulley,belt tensioner pulley and idler pulley all by hand and they were all ok. I then started the car with belt off for a few seconds and the noise still was comming. I'm going to try the MMO as you mentioned and see what will happen and report back. I doubt the noise is comming from the accessory area as it's very loud and comming from the middle of the engine. Link to comment Share on other sites More sharing options...
TDK Posted June 12, 2005 Report Share Posted June 12, 2005 Arash, This thread does not sound too good... Although it was coincidental with changing the accessory belt, if the noise does not go away without the belt then ...ratz Have you tried using a stethoscope (carefully - as to not get tangled up). The relatively long frequency between knocks (you noted 7-seconds as I recall) is interesting. Can you carefully time the noise again at idle? Assuming a 600-rpm idle, 8-cylinders, and a 4-stroke cycle, then each cylinder fires 18.75 times every minute or every 3.2 seconds. Without accurate timing, it might be easy to "mind-stretch" 3.2 seconds into 7 seconds - in particular when under this kind of concern. You might be able to isolate the source of the noise by disconnecting one spark plug at a time. If the noise quiets (when the power stroke is subdued), then there may be a problem with a given piston/wrist pin/connecting rod etc. At this point, I would not run it much without consideration for something serious going on inside. Its a lot cheaper to change bearings etc than a complete engine - if something actually comes loose inside. Good luck Add power to leave problems behind. Most braking is just - poor planning. Link to comment Share on other sites More sharing options...
Scotty Posted June 12, 2005 Report Share Posted June 12, 2005 I just started the car and released the tensioner with the special arm and the noise was the same. Then I turned the car off,opened the belt, and cheched power teering pulley, alternator pulley,belt tensioner pulley and idler pulley all by hand and they were all ok. I then started the car with belt off for a few seconds and the noise still was comming. I'm going to try the MMO as you mentioned and see what will happen and report back. I doubt the noise is comming from the accessory area as it's very loud and comming from the middle of the engine. The MMO is only for the valve train if a lifter is dirty. I would have bet that the tight belt damaged an accessory bearing. Good luck with this. Link to comment Share on other sites More sharing options...
Arash Posted June 13, 2005 Author Report Share Posted June 13, 2005 I could not find the MMO in Canadian stores. Instead I used an equivalent liquid which was designed for noisy valve lifters and similar problems. I changed the oil and filter and added the liquid and let it idle for 40 minutes but it didn't solve any problem. I'm 100% sure the loud ticking is not coming from the accessory area and comming from the middle of the engine. I also checked all plugs by disconnecting them one at a time but that didn't solve any problem either and it's totally independent of the spark plugs. The noise is completely random at idle. When you increase RPM it becomes a consistent and loud knock with high frequency. It's not a single tone noise. I'm having both ticking and knocking but the ticking sometimes disapears at idle but the knock is presistent, more than twice a second. The knock seems to come from the lower part of the engine. Tommorow I will tow the car to a reputable GM dealer for diognosis and report the results to you guys. Thanks for all the help so far. Link to comment Share on other sites More sharing options...
Scotty Posted June 13, 2005 Report Share Posted June 13, 2005 Good Luck Link to comment Share on other sites More sharing options...
Arash Posted June 14, 2005 Author Report Share Posted June 14, 2005 bbobynski, thanks for your reply. No I didn't open this engine for head gaskets. In fact, I've never even opened the beauty cover as all my repairs were on other parts like suspension, radiator etc. I will do what you say and report back. The oil filter is still in the garbage. Today I took the car to a trusted dealership for diagnosis and they said it's either the rod bearing or the part which connects the piston to the connecting rod; sorry I forgot its name. They recommended me to buy a used engine as it's the cheapest option. They are quoting $3500 CAD engine + $1500CAD labour. The used engine has a three month warranty but they're saying that non of the gaskets were changed and l may still have trouble with oil leaks and etc. I have a factory service manual and have done many repairs so far on the car. Can I buy a crane and open the engine with my brother and gradually start repairing it? what do you think? I checked a few places online and the cheapest used engine I could find was $2500 USD without S&H. Do you know any good source. AC Delco is quoting me $7000 CAD for a remanufactured engine with 3 years 80,000 warranty. So far the best option remaining for me is selling the car to a mechanic or auto salvage. If I can repair the current engine myself I may have a go at it. All suggestions will be appreciated. Link to comment Share on other sites More sharing options...
TDK Posted June 14, 2005 Report Share Posted June 14, 2005 Arash, Too bad about the diagnosis. Hopefully you will have good news (as in no metallic flakes in the oil) and find some other reason that is fixed easier and cheaper. It might work out better to get another similar Caddy and part out the old one with 96,000-miles. If able, keep it for a bit to mix and match the best of both vehicles to some degree. Check out the following Ebay link to a $5,000 or so 1994 Eldorado with 79,000-miles. Sorry, I could not recall if you had an STS or Eldo. http://cgi.ebay.com/ebaymotors/ws/eBayISAP...sspagename=WDVW I would guess there are better deals to be found for sure and I'm certain you will consider a number of options before dropping $5,000 into another used engine. As far as repair, I think that head gaskets are a relatively straight forward job with good results (but still a lot of work). But a total crank/rod bearing job with other remaining damage possible along with metal bits all through the engine/oil . . . are another thing to think about. I'm not sure I would trust it for all the work into it compared to something else. Again, too bad but - Good Luck Add power to leave problems behind. Most braking is just - poor planning. Link to comment Share on other sites More sharing options...
Scotty Posted June 14, 2005 Report Share Posted June 14, 2005 I am sorry to hear that Arash, do you have junk yards near you? I will make a call tomorrow and see how much a NS is from my guy....I have been buying 4.9's for $400 to $500, and I know they have a bunch of NS's in stock.... I will report back, 1994, STS. I wonder what other engines will fit year wise... I also think you need to get an STS/ETC engine... as the engines are different than non STS/ETC engines I have shipped an engine to Amsterdam, so shipping one to you should not be a problem...we needed to use plastic pallets as the wood pallets can transport insects and beetles.. Link to comment Share on other sites More sharing options...
Arash Posted June 14, 2005 Author Report Share Posted June 14, 2005 Scotty, Thanks for searching the used engine. We do have junk yards located about 50 km away and I called threeof them today already. One of them had the used engine selling for $3500 CAD. Majority of junk yards don't sell parts for Cadillac in Vancouver. There are few Sevilles/Eldorados here. I opened the oil filterand there are metallic parts in it indeed. Take a look at the pictures. The metal pieces are small. Link to comment Share on other sites More sharing options...
Scotty Posted June 14, 2005 Report Share Posted June 14, 2005 Scotty, Thanks for searching the used engine. We do have junk yards located about 50 km away and I called threeof them today already. One of them had the used engine selling for $3500 CAD. Majority of junk yards don't sell parts for Cadillac in Vancouver. There are few Sevilles/Eldorados here. I opened the oil filterand there are metallic parts in it indeed. Take a look at the pictures. The metal pieces are small. I will call my local junk yard for you. I have about 20 or 30 here on long Island. But I know for sure that I can get it cheaper. I will do my best. I am curious what Guru thinks about that debris. I will let you know what I find out, Mike Link to comment Share on other sites More sharing options...
Scotty Posted June 14, 2005 Report Share Posted June 14, 2005 My guy has a 94 NS with 90,000 miles on it that he said he heard run and it ran good for $1,000, it is not the STS engine its the SLS engine (275 HP). It can be shipped. Mike Link to comment Share on other sites More sharing options...
Arash Posted June 14, 2005 Author Report Share Posted June 14, 2005 Thanks Scotty. What is the warranty on the engine? I appreciate your time and effort. Please also don't spend too much time on it. I've already checked the www.car-part.com which has a list of many many junk yards across Canada and USA. Link to comment Share on other sites More sharing options...
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