w-bodys_are_the_best Posted October 24, 2009 Report Share Posted October 24, 2009 This is my brother's car, 3100 or course. It did this about 3 weeks ago and after replacing the starter he burnt up, we narrowed it down to the ICM. I gave him the ICM and coilpacks that I took off my 94 Cutlass before I junked it and it fired right up. Fast forward to last thursday, and it's doing it again. He's getting plenty of fuel but no spark. My gf's dad also had a 3100 ICM and coilpacks sitting around, so my brother bought that from him, that didn't work, so he went and replaced the crank sensor, still won't fire. He's getting pissed and doesn't want to keep puting money into it. **EDIT: I just talked to him again and told him to double check all the electrical plugs on the ICM and crank sensor. I also asked him how it died and he said it started bogging down and almost didn't make it up a hill. He then pulled off on a gravel and it completely died. He said they have gas sprying out at the schrader valve, but I told him to release the pressure with a rag around the schrader valve with the key off of course. I tolf dim to then turn the key back on then try the valve again to make sure it builds pressure back up. The way it died sounds like the way my 94 Cutlass died when the fuel pump shit out on it. Does the 98 3100 have a cam sensor? Would a bad one cause it to not fire? Quote Link to comment Share on other sites More sharing options...
tunerlover3 Posted October 24, 2009 Report Share Posted October 24, 2009 Yes it has a cam sensor. No, it would still run if the cam sensor was bad. It would just run in limp mode. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted October 24, 2009 Report Share Posted October 24, 2009 step 1: check for spark. pull one plug wire from a spark plug and stick a phillips screwdriver in the end. lay in on the intake and crank. look for a nice blue spark. if spark = yes step 2: try running on starting fluid. Quote Link to comment Share on other sites More sharing options...
w-bodys_are_the_best Posted October 25, 2009 Author Report Share Posted October 25, 2009 The did the spark test and nothing, plenty of fuel at the schrader valve, and it builds up pressure after being relieved. I had one thought I relayed to him. My coils and ICM fixed the problem 3 weeks ago. This time he tried my gf's dad's coils and ICM, didn't fix it, so they replaced the crank sensor and still nothing. I told him it could be possible (but not likely) that the crank sensor was bad and my gf's dad's coils and ICM he put on there may also have been bad (though he said they were known to be good). I told him to throw my coils and ICM back on just for shits and giggles. Someone else thought the timing chain may be the problem and said they'd help him fix it. I let him borrow the lincoln for now since I was planning on parking it. He spoke of possibly trading the lincoln for the Lumina, and while that would be a good deal for me, he's my brother and I don't see the lincoln being a long lasting car without sticking money into it. The batery is shot and lasts about a week after a good overnight trickle charge. The tires are too wore for winter, and the airbags will need attention by springtime. He'll be screwed if it snows and it actually stays. Quote Link to comment Share on other sites More sharing options...
tunerlover3 Posted October 25, 2009 Report Share Posted October 25, 2009 If the timing chain was broken, it would still get spark. Does he have a friend with a scanner? I would check to see if the scanner will even read the cars RPM. If it doesnt, recheck the CKP. Quote Link to comment Share on other sites More sharing options...
95 vert Posted October 25, 2009 Report Share Posted October 25, 2009 Try unplugging the cam sensor. IIRC it should have a long crank time but start if it is the cam sensor. Also, check the crank sensor wiring. Sometimes this gets oil soaked and can short together inside the convolute tubing. Quote Link to comment Share on other sites More sharing options...
1990lumina Posted October 25, 2009 Report Share Posted October 25, 2009 I'm sure you guys would know if it the timing chain - if the motor did still turn over it would have no compression/sound completely different. Quote Link to comment Share on other sites More sharing options...
carkhz316 Posted October 25, 2009 Report Share Posted October 25, 2009 You might have fuel squirting out of the scraeder valve, but if the pressure isn't enough, it won't start either. Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted October 25, 2009 Report Share Posted October 25, 2009 You might have fuel squirting out of the scraeder valve, but if the pressure isn't enough, it won't start either. x2 Quote Link to comment Share on other sites More sharing options...
w-bodys_are_the_best Posted November 1, 2009 Author Report Share Posted November 1, 2009 Well, I got to look at this car for the first time tonight since the problem started, and I can't believe they didn't figure it out. As soon as he cranked it over I could tell from the sound what the problem was. It turns out it suffered the same fate as my Z24, it's got a broken timing chain. I've been told that's pretty uncommon in a 3100, but it happened. I heard it and right away found a flashlight, pulled the oil cap and watched each of the 2 visible rocker arms while he cranked it over, neither moved at all. $46 for a timing chain set on rockauto, so we're going to throw a new one on. Quote Link to comment Share on other sites More sharing options...
95 vert Posted November 1, 2009 Report Share Posted November 1, 2009 Cam could be broke. Seen that plenty of times. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted November 1, 2009 Report Share Posted November 1, 2009 x2! Quote Link to comment Share on other sites More sharing options...
dodgethis Posted November 1, 2009 Report Share Posted November 1, 2009 but the 3100 is non-interference, so a new chain would all be that needed right? Quote Link to comment Share on other sites More sharing options...
Crazy K Posted November 1, 2009 Report Share Posted November 1, 2009 but the 3100 is non-interference, so a new chain would all be that needed right? if only the chain is bad... Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted November 1, 2009 Report Share Posted November 1, 2009 3100 are truly non-interference? Quote Link to comment Share on other sites More sharing options...
w-bodys_are_the_best Posted November 4, 2009 Author Report Share Posted November 4, 2009 I talked to my brother again finally this morning. It is for sure 100% is a broken cam. They pulled the valve cover and there is metal everywhere he said (though I never saw any looking through the oil hole) and he said there were 4 dropped valves. I'll try and get pictures next time I am around it. On the plus side, he is keeping the car for parts and getting a 94 Cutlass coupe for $300 from the guy who helped him pull the valve cover and determine the problem. What would cause a cam to break? I the only thing I could think of is if a valve seized and the cam broke from trying to open that valve. Quote Link to comment Share on other sites More sharing options...
Brian P Posted November 4, 2009 Report Share Posted November 4, 2009 Broken cams are known to happen. A lot of times you'll hear about it occuring after a major intake gasket failure which allowed coolant into the crankcase. The coolant drenches the camshaft first and causes the valvetrain components and bearings to suffer, and some time later after the repair, the cam fails. The cams are hollow-core with lobes that are set in place after a high strength steel ball is forced thru the core, however GM has been doing this to the LS V8's with no issue. It's a manufacturing problem with these specific cams in the late '90s model 3100's (usually '97-99). Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted November 4, 2009 Report Share Posted November 4, 2009 Must be what happened to my brothers 3100. Quote Link to comment Share on other sites More sharing options...
95 vert Posted November 4, 2009 Report Share Posted November 4, 2009 I've found on 3100's with a broken cam that the cam bearings are worn badly causing the cam to "walk" up and down in the block. This in turn makes the cam break. As Brian P said, usually after gaskets fail and coolant is introduced into the crankcase causing excessive bearing wear. Normally, the block is beyond repair after the cam breaks because there is too much damage to bearing seats. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.