: Northstar Died? no vacuum, no compression on cyl 6.



deepthinker22
05-17-09, 12:29 PM
Hey, I just recently aquired a 1999 seville sts. I even just drove it back about 2000mi from AZ to MI with no problems at all. However this will come into play latter, the guy who was helping me drive decided to put E-85 into it for two fillups when passing through iowa, and I think once in nebraska. Anyways after a few weeks at home with it, I was driving home up a hill (been running premium now), when I got a loud ping with the service engine light on, after I stoped the car began sputering and died. Well I can get it to start sort of, with the throttle open aways and this is how I did some testing to find the problem. I get little to no vacuum, cylinder six shows zero compression, low compression on other cylinders, (I havn't tested the other bank yet for obvious reasons. I also tried pumping air into cylinder six while in the compression stage, and It will not hold any pressure it is leaking through the valves. Because of the low to zero vacuum the engine has been running very rich. So far, I think the E-85 burning hotter could have started destroying the valves. The car did have many rough idles after the E-85, but once the engine warmed up it went away. So far the mechaninc said, due to the hastle of rebuilding this engine, it might be easier just to get a new one. So far the cheapest I have found is $4,300 on the internet. I have access to many tools including a 5-axis CNC mill if I need to totally upgrade the block or even make new pistions on that thing. Anyways, has anybody ever had this same problem or can think of a know issue that would cause it. Oh, one more thing, I looked at a graph for the burn information on the spark plugs or whatever it was called. Thats how I knew to check cyl 6. It showed a very low peak with no duration to the spike. The cylinders next to it which had decent compression didn't have this, and the other cyl from the other bank were also very low. Again, thanks for any help I can get.

Ranger
05-17-09, 12:55 PM
WOW! I think the guy that was "helping" you owes you some money. I'm not sure what E85 will do, but from what you are saying it sounds like it will burn valves. The only weak point in these (pre 2000) engines is the head gaskets. I'd get a salvage engine. Buy the stud kit from Jake http://www.northstarperformance.com and stud the new engine before you install it with new head gaskets. Then it will last forever.

Submariner409
05-17-09, 04:33 PM
GM specifically states that E85 shall not be used in a Northstar not so calibrated. You have burned the valves and rings out of the engine. You should never have tried to run the car on a fuel not recommended in the owner's manual. If you can reach back over your shoulders with a baseball bat held in both hands, hit your "friend" in the butt, real hard.

Total overhaul. Top to bottom.

Forget your CNC work. There are no block upgrades. Rebuild the engine to factory spec using OEM parts (the cylinder bores are the determining factor here) or talk to Jasper or someone else about getting a warrantied long block.

For serious engine replacement options, cash on the barrel head, no jerk-arounds, call Luke in parts at Lindsay Cadillac over there ------>

(Sort of curious that back in March you were talking of doing a lot of ill-advised "upgrades and mods" to "your Cadillac", and now you just recently picked up an STS and drove it home. What's the real skinny - did this thing blow up on the drive home or did your mods and experiments blow it up ???)

Harry Yarnell
05-18-09, 07:54 AM
Did you check compression on BOTH banks? My recent posting on a similar matter showed low (30-45#) on the front bank, but normal comp. on the rear bank. Problem was a intake cam that jumped time. Since I bought this car for parts, I didn't know the history.

codewize
05-18-09, 09:40 AM
I think it's strange that the car even ran on E85. We have a station here that apparently exceeded the E10 factor because every time I get fuel there, which I don't anymore. I get lean codes all day long.

I can't imagine she'd even run on E85 without many a codes.

Yes I've tested that theory. I can drive the car forever on Sunoco but as soon as I put in Mobil, at least from this one station, I get lean codes.

deepthinker22
05-18-09, 07:03 PM
Did you check compression on BOTH banks? My recent posting on a similar matter showed low (30-45#) on the front bank, but normal comp. on the rear bank. Problem was a intake cam that jumped time. Since I bought this car for parts, I didn't know the history.

I would have thought the same thing, but on the same bank, normal compression for other cylinders, but number 6 has NO compression. Gauge dosn't move at all.

deepthinker22
05-18-09, 07:10 PM
GM specifically states that E85 shall not be used in a Northstar not so calibrated. You have burned the valves and rings out of the engine. You should never have tried to run the car on a fuel not recommended in the owner's manual. If you can reach back over your shoulders with a baseball bat held in both hands, hit your "friend" in the butt, real hard.

Total overhaul. Top to bottom.

Forget your CNC work. There are no block upgrades. Rebuild the engine to factory spec using OEM parts (the cylinder bores are the determining factor here) or talk to Jasper or someone else about getting a warrantied long block.

For serious engine replacement options, cash on the barrel head, no jerk-arounds, call Luke in parts at Lindsay Cadillac over there ------>

(Sort of curious that back in March you were talking of doing a lot of ill-advised "upgrades and mods" to "your Cadillac", and now you just recently picked up an STS and drove it home. What's the real skinny - did this thing blow up on the drive home or did your mods and experiments blow it up ???)

No, No mods at all yet (havn't had it at home). Plus if I blew it up I would know right away and woudn't need advice. I just wanted to see if anybody has heard about this. The "friend" sitll insits there is no way that the E-85 did that, strickly because the engine was "old" (at 135K mi). However, I now think it was a combination of old lady who owned it before who never opened the throtle, and on the way back with a full load in the vehivle the person driving (not me) opened the throttle several times with that shit in the car. I told him when he was filling up "Dont put that shit in my car." But oh well.

Not many junker engines around here, plus I heard rebuilding these things it is hard to come by oversized bearings and such. Those are expensive for me to make and might not be worth it, Same with piston rings, so I dont want to pull the crank or pistons if I have too. Apparently there is an issue with threads comming out when pulling the heads? is this true? Also I can't find anything on rebuilding these heads, which look like alot more work than I expected.

I will post again as soon as I can get ahold of a camera to look in cyl number 6. In the meantime I'm looking for a new or used replacement engine. used under $1.5k and new preferably under $2.5k. I need to get this thing running to head back to AZ.

One more thing it didn't blow on the way home, but just after I got back, and dared to open the throtle once I got some premium. even then it wasn't much of an opening just a little to maintain speed on a steep hill.

Ranger
05-18-09, 09:32 PM
Yes, the threads sometimes do pull. More so on the 97-99's. If you get another engine, pull the heads, drill and tap the bolt holes before you put it in and install Timeserts http:/www.timesert.com or Jake's stud kit http://www.northstarperformance.com. If they go after you install it, you'll have to pull the drivetrain again.

deepthinker22
05-23-09, 01:32 PM
anybody no where to find a replacment 300hp engine. The only thing I have found is the 275hp ones around here. I'm also looking for a cheap replacement. Latley I have had to drive the KW home from work. My boss isn't too happy about it either, and the neighbors arn't sure about the 8.3L turbo deisel firing up at 5:30AM.

deepthinker22
06-09-09, 09:55 PM
Ok, Update. I replaced the engine, I drove it for a day, then some trouble codes started poping up, and now I have major electrical issues and I have no where to start. The first symptom was my spedometer droping to zero, and the transmission failing to shift, go into gear, stay in lockup etc. Then I lost the tac and the engine stalled once or twice. It was running rich, hard to start. The only thing I could do consistantly was travel at low speed in reverse. I checked the codes multiple times but lost the sheet. Couple I remember is crank pos. sensor, stall condition, MAF sensor, and an O2 sensor. There were several other codes I got from the onboard diagnostics, but I didn't have the resources to look up anything but P codes. Somebody told me that it was all because of the MAF sensor, which seems like total bullshit to me. I don't see how this is possible. I checked all my grounds and connections, everything seems fine. The only thing I did to it so far was add some belt dressing to stop a squeek. BTW, same fuel injectors. Just added some cleaner, Premium fuel, New spark plugs. I think I am going to check some of the wires for continuity to the wiring harnesses and see if there may be any pins missing. But it just dosn't make sense.

zonie77
06-09-09, 10:26 PM
I would get the locations of ALL the grounds and double check them. I did not fully tighten one and about two months later had weird problems. That one came loose and caused multiple problems. The circuits all went to one ground low on the passenger side .

I did not find it visually, had to look at the manual to find it.

deepthinker22
06-17-09, 04:42 PM
Update: VSS fixed (bad connection), crank pos sensor replaced. (that sucked). The only thing I'm left with is one unconfirmed ground wire, and the code P1350 it throws at me. Also when it throws this code it goes into limp mode. I had the ignition module replaced no problems sense, and I'm hopping it is gone now. When it did go into limp home, all I had to do was turn the car off and then back on again and I was good for the next 3 or 4 drives. After this...I probably will never buy a Cadillac again.