rbrantlee Posted June 29, 2005 Report Share Posted June 29, 2005 My 98 STS is in the shop to have the head gaskets replaced(GM is paying for half and giving me warranty price since they failed at 35K miles). The service manager summoned me to the shop this morning. They pulled the cam covers and sludge is everywhere. You can't even see the cam bolts. He pulled the oil filter and jelly-like sludge came out. I can't understand this part because I have changed the oil twice and never saw sludge in the oil or oil filter either time. But I don't think they're trying to pull a fast one on me either. Here's my problem. The manager gave me three options. 1) Replace the gaskets and leave as much of the sludge alone as possible. 2) Replace the gaskets and do a special chemical flush. 3) Remove the pan, tear down the crankcase and manually remove the sludge and clean the oil pickup screen, check bearings, replace half seals, etc. Would cost me about $800 extra. I have the money. Everyone always says to leave the sludge alone-you'll never get it all and if you disturb it you could mess up a bearing. But if iI don't, I run the risk of clogging up the screen eventually and losing the engine. I'm damned if I do and damned if I don't. What should I do? Any and all professional opinions would be greatly appreciated. Link to comment Share on other sites More sharing options...
JIMDTS Posted June 29, 2005 Report Share Posted June 29, 2005 Well I guess it all depends if you are going to keep the car. As to how I would go about this reapair. Since the engine is out I would have them reseal the lower engine Along with timeserting the head bolts which is another issue their is a chance that the head bolts could pull out down the road if this is not done I'm not sure of the dealer prices about dropping the pan and reseal cleaning the sump area should be an easy job but parts are not cheap. It sounds like the coolant mixed with the oil and just sludged up.Read up on timeserts on the forum do a search with the Keyword timeserts.It's sort of a catch 22 If I wanted to keep the car I would go through the engine if not just get the head gaskets + flush and hope for the best and dump the car Even if you get the whole 9 yards things can still go wrong So i guess it's your call SOunds like a nice low milage sts so it may be worth it if you are going to keep the car I doubt you have a bearing problem but you never know till you open it up I would ask the dealer to have a gm rep look at your engine and get his or her imput since they are in it for half of the head gaskets.. Good Luck Jim Link to comment Share on other sites More sharing options...
Ranger Posted June 30, 2005 Report Share Posted June 30, 2005 I too would suspect coolant in the oil but Guru has mentioned that the Northstar is built so that can't happen. Have you owned it since new? Have there been any additives put in that you are aware of? There is something unexplained going on to be in that condition at 35K. Link to comment Share on other sites More sharing options...
Matt Posted June 30, 2005 Report Share Posted June 30, 2005 Just wondering, what would another N* engine go for? and what year would that be? Link to comment Share on other sites More sharing options...
navion Posted June 30, 2005 Report Share Posted June 30, 2005 My 98 STS is in the shop to have the head gaskets replaced(GM is paying for half and giving me warranty price since they failed at 35K miles). The service manager summoned me to the shop this morning. They pulled the cam covers and sludge is everywhere. You can't even see the cam bolts. He pulled the oil filter and jelly-like sludge came out. I can't understand this part because I have changed the oil twice and never saw sludge in the oil or oil filter either time. But I don't think they're trying to pull a fast one on me either. Here's my problem. The manager gave me three options. 1) Replace the gaskets and leave as much of the sludge alone as possible. 2) Replace the gaskets and do a special chemical flush. 3) Remove the pan, tear down the crankcase and manually remove the sludge and clean the oil pickup screen, check bearings, replace half seals, etc. Would cost me about $800 extra. I have the money. Everyone always says to leave the sludge alone-you'll never get it all and if you disturb it you could mess up a bearing. But if iI don't, I run the risk of clogging up the screen eventually and losing the engine. I'm damned if I do and damned if I don't. What should I do? Any and all professional opinions would be greatly appreciated. rbrantlee, What color is this sludge? Is it a grayish white color or is it black or brown? If the sludge is from anti-freeze in the oil, then it must be removed. Additionally, antifreeze in the oil is VERY detrimental to rod and main bearings. I would insist that the bearings be inspected and if damage is found, replaced. Personally I can't see leaving any sludge in any engine unless you are selling it tomorrow! Guru has said that the N* is much less likely than the 4.9 to get antifreeze into the oil, but it is not impossible. I would have the mechanic inspect the cylinder that was exposed to the coolant to see if the cylinder wall shows excessive wear. Another way antifreeze could get into the oil would be if the cylinder head leaked coolant into the timing chain galleries. Personally I find the accumulation of any amount of sludge a reason for concern. The amount of sludge that you are describing would alarm me. The other explanation would be that the car was "short tripped" most of it's life before you bought it. If an engine is never brought up to operating temperature then the moisture that is drawn into the crankcase or formed by combustion byproducts never gets a chance to be vaporized & drawn off by the crankcase vent system. A car that has averaged 5000 miles a year or less could be a candidate for generating sludge in this manner. However, your statement that you didn't see this sludge in the filter before, and it is in it now, leads me to suspect the antifreeze as a primary source of the sludge. The short tripping may or may not have contributed to the sludge problem. If I were you I would go with the extra $800.00 now. If the sludge is indeed caused by antifreeze, then the bearing change is mandatory in my opinion. Get ALL the sludge out that is possible. Stay away from any "chemical flush"! As soon as I got the car back I would put about 100 miles on it in a single trip, change the oil while it was still hot. drive it about 1000 more miles, Change the oil again (while it is hot) & then go back to your normal oil change by DIC procedure. This should flush out any crud left from the rebuild. Always drain the oil while it is hot. One of the things that I do, time permitting, is let the oil drain overnight. Leave the filter off while the oil is draining. You would be surprised at the amount of oil that will drain out overnight. More than 1/2 a quart. Good Luck, Britt Britt Link to comment Share on other sites More sharing options...
JohnnyG Posted June 30, 2005 Report Share Posted June 30, 2005 OK, let's look at the facts. If I am correct, you have a 1998 Cadillac with 35,000 miles on it! If this is correct, YOU'RE GONNA HAVE SLUDGE!!!! Are you the original owner? If so, you have 7 years of driving back and forth to the store, which NEVER gets the oil hot and never drives off the moisture in the oil...YOU'RE GONNA HAVE SLUDGE!!! Or the car sits in the garge a lot, but you go out and start it every so often to "keep the battery charged"...YOU'RE GONNA GET SLUDGE from doing that! This is called SEVERE SERVICE, and you should have changed your oil according to the severe service schedule, did you do this? What oil have you been using? How often did you change it? You said in your post that you changed the oil twice, is that it? You should have changed the oil at least 7 times since the manual states that the oil should be changed at least that often; the severe service schedule probably calls for every 6 months. Or did you HAVE it changed the other 5 (12) times by someone else? Do you live in Alaska or Florida? If you live in Alaska, YOU'RE GONNA HAVE SLUDGE!!! Take option #2, and keep the $800 in the bank. Get the car back, go to church and say a blessing for GM for paying part of the cost of repairs, and tell all your friends that you will never own a piece of Japanese junk ever in your life. Drive the car about 500 miles ALL IN ONE TRIP, get it back home, change the oil again and keep the car forever. It takes at least 20 minutes of running, 10 of them actually driving, to heat the oil up sufficiently to recover from the moisture produced by a cold start. Begin taking the car for a 30 minute ride at least once a month and the sludge won't come back. Change the oil at least every 6 months from here on out. Any additional moisture in the oil, say, from a HEAD GASKET LEAK, will make the sludge problem worse, much much worse. Sorry if I sound mean, but your post leaves out a LOT of vital details on the ownership time, useage, driving habits, location, maintenance, state of repair (poor), and products used. ALL of these things are important to tell you exactly WHY the sludge formed, and to help you avoid more problems in the future. Never underestimate the amount of a persons greed. Link to comment Share on other sites More sharing options...
Bob*97 SLS Posted June 30, 2005 Report Share Posted June 30, 2005 It would be that, if GM is willing to pay for half and giving you warranty cost on your half, there is already a solution. You don't get GM or anyone else to give a "blank check" for any repairs you like to have. What did they say will be done.? Link to comment Share on other sites More sharing options...
rbrantlee Posted June 30, 2005 Author Report Share Posted June 30, 2005 JIMDTS-Timeserting was agreed to by the dealer. Ranger-Sorry. I forgot to say I bought the car at 30K. Unfortunately, there were no service records(live and learn) but I got it for a good price. Started losing coolant internally at 35K. I haven't added any additives to the oil. Matt-You can get a new crate Northstar off the internet for about $4000 shipped. Britt-The sludge was black/brown, not milky. But it is the worst I've ever seen. My dad was a mechanic and I've torn down a few engines. It is perplexing. Sounds more like coolant than short-tripping because I didn't see sludge until now. I'm going to have it torn down and inspected. Thanks. Bob*SLS-GM is only paying 50% for the gaskets/timeserts. The only reason I called GM and asked for help is because Guru said there is no reason a 98 Northstar should lose head gaskets at 35K. I am happy and grateful to GM. Link to comment Share on other sites More sharing options...
rbrantlee Posted June 30, 2005 Author Report Share Posted June 30, 2005 OK, let's look at the facts. If I am correct, you have a 1998 Cadillac with 35,000 miles on it! If this is correct, YOU'RE GONNA HAVE SLUDGE!!!! Are you the original owner? If so, you have 7 years of driving back and forth to the store, which NEVER gets the oil hot and never drives off the moisture in the oil...YOU'RE GONNA HAVE SLUDGE!!! Or the car sits in the garge a lot, but you go out and start it every so often to "keep the battery charged"...YOU'RE GONNA GET SLUDGE from doing that! This is called SEVERE SERVICE, and you should have changed your oil according to the severe service schedule, did you do this? What oil have you been using? How often did you change it? You said in your post that you changed the oil twice, is that it? You should have changed the oil at least 7 times since the manual states that the oil should be changed at least that often; the severe service schedule probably calls for every 6 months. Or did you HAVE it changed the other 5 (12) times by someone else? Do you live in Alaska or Florida? If you live in Alaska, YOU'RE GONNA HAVE SLUDGE!!! Take option #2, and keep the $800 in the bank. Get the car back, go to church and say a blessing for GM for paying part of the cost of repairs, and tell all your friends that you will never own a piece of Japanese junk ever in your life. Drive the car about 500 miles ALL IN ONE TRIP, get it back home, change the oil again and keep the car forever. It takes at least 20 minutes of running, 10 of them actually driving, to heat the oil up sufficiently to recover from the moisture produced by a cold start. Begin taking the car for a 30 minute ride at least once a month and the sludge won't come back. Change the oil at least every 6 months from here on out. Any additional moisture in the oil, say, from a HEAD GASKET LEAK, will make the sludge problem worse, much much worse. Sorry if I sound mean, but your post leaves out a LOT of vital details on the ownership time, useage, driving habits, location, maintenance, state of repair (poor), and products used. ALL of these things are important to tell you exactly WHY the sludge formed, and to help you avoid more problems in the future. You did sound mean. My fault. It's been awhile since I posted and forgot to mention I bought the car at 30K. I've put about 10K on it in about 8 months. Plenty of WOT's. Changed oil/filter twice since. I live in Dublin, GA. That's right above Florida. Short-tripping would make sense, except why see sludge now? I think I'm going inside while I've got the engine removal labor for free, just to make sure. Link to comment Share on other sites More sharing options...
jhall Posted June 30, 2005 Report Share Posted June 30, 2005 Hi Guys, A little info. See attached pic of a N* with the head removed and note the coolant passage around the cylinder. It is almost impossible for coolant to get into the oil when a head gasket fails on a N*. The pressure from the piston forces gases out of the cylinder into the coolant chamber. Coolant can not move into the cylinder unless the gasket has a gap blown out of it at the cylinder seal ring area (not usually the case). As far as the sludge issue goes, it sounds like it was driven on short hauls or poor quality oil was used. I pulled my N* down at 130K miles for a head gasket and the engine was pretty clean (no sludge). I do lots of interstate driving. JohnnyG and Navion are right - Leave the sludge alone and skip the chemical "cleaners". The chances of a large quantity of sludge getting loose and plugging the oil pickup screen a practically nil. Run the car and change the oil as indicated in their posts and you'll probably be just fine. Link to comment Share on other sites More sharing options...
rbrantlee Posted June 30, 2005 Author Report Share Posted June 30, 2005 Hi Guys, A little info. See attached pic of a N* with the head removed and note the coolant passage around the cylinder. It is almost impossible for coolant to get into the oil when a head gasket fails on a N*. The pressure from the piston forces gases out of the cylinder into the coolant chamber. Coolant can not move into the cylinder unless the gasket has a gap blown out of it at the cylinder seal ring area (not usually the case). As far as the sludgge issue goes, it sounds like it was driven on short hauls or poor quality oil was used. I pulled my N* down at 130K miles for a head gasket and the engine was pretty clean (no sludge). I do lots of interstate driving. I totally agree with your logic. But why would I see sludge out of the oil filter now, and not out of the oil or oil filter the last two times in 10K miles? Link to comment Share on other sites More sharing options...
Ranger Posted June 30, 2005 Report Share Posted June 30, 2005 I too do mostly highway driving and no short trips. I recently got a bore scope and decided to have a look inside the cam covers. At 100k there is NO sludge at all. Link to comment Share on other sites More sharing options...
rbrantlee Posted June 30, 2005 Author Report Share Posted June 30, 2005 Sludge like you describe is really really unusual. First, forget worrying about the bearings. Even if lots of coolant got into the oil it will NOT hurt the bearings. Old wives tale thre about coolant damaging bearings Maybe back in yesteryear with lots of lead and zinc in bearing shells but the hard aluminum bearing inserts of today will not be harmed by coolant. Not at all. I would have them wash the deposits off the heads as much as possible and forget about it, personally. Can you post any pictures just out of curiosity to see what this sludge looks like..?? I would have them check the engine oil cooler in the radiator (if your car has one). Possibly it is failing and allowing coolant to migrate into the oil at the oil cooler when the engine is shut down and cooling system pressure is higher than the oil pressure...which would be zero when the engine is shut down. Get it put back together and start doing some frequent oil changes...like every 2 or 3 K. Forget any sort of chemical flush. Let the detergents in repeated fresh oil fills do the cleaning. Are you SURE of the condition of the deposits...?? This isn't some sort of hose job your are getting is it....??....like some sort of jello poured over the parts or something...??? I have NEVER seen a Northstar sludged up like you describe even when coolant was in the oil and the engine was short tripped. Just hard to believe when we have tried to make sludge. Maybe the previous owner was using that SA oil at the doller store in the engine....oil with no detergents or dispersants....and no anti-wear additives. My car is 50 miles away because the local dealer refuses to timesert all head bolt holes and wonders why he loses money on head gasket repairs due to call backs. I will try to get pics to post. I will get them to check out the oil cooler in the radiator. I don't think it's a snow job. They're not demanding that I address the sludge problem. Just giving me options. OK-I'll just go for the gasket/timesert repair and progress as suggested by several repliers. Thanks. Link to comment Share on other sites More sharing options...
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