TGPilot Posted March 13, 2005 Report Share Posted March 13, 2005 You need to pull the valve cover to see if any of them are moving... 8) well i just went and looked in the oil fill cap hole while my brother cranked the engine and there is NO valvetrian movement at all That little hole you will see two of 16 Rocker arms. That is not going to say shit if the cam is busted before those 2 rockers! The cam drive source is all the way down on the other end of the motor. whoa...so i could be looking at a broken cam?!?!!?? I don't know Josh! You are the one with the motor in his front yard. You need to dig into it and see what is causing the rockers to not move! Now Josh...if none of the rockers are moving then think. What makes the cam rotate? The chain connects the crank gear to the cam gear. You need to pull the front of the motor apart to see the components that make the cam go round and round. It could be the crank gear keyway is stripped out and free spinning, it could be the chain is busted, it could be the cam gear teeth are made of teflon (not sure what engines GM did that to) and they shattered, could be the cam shaft busted right at the cam gear bolts, or could be the cam broke down the shaft somewhere (not likely as you said none of the front bank rockers are moving). 8) Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted March 13, 2005 Report Share Posted March 13, 2005 1st have you looked at the valvetrain to see if the rockers are moving while cranking? I have never personally seen a T-chain failure and i believe that it is a non-interference engine. 2nd have you checked compression? at least pull a plug out and stick your finger over the hole and crank it-it should have no problem blowing your finger outa the way-or use a compression Gauge 3 CPS on these cars can fail, AND still put out a signal-it is a hall effect sensor and if a winding or two is shorted it will reduce the sensors output voltage when triggered by the tone ring on the crank. I have seen weak/intermitent spark from them before (i have changed ~50-60 of em), the PCM has a sensor threshold for EMI and when it puts out a low signal it can cause problems. BTW almost always when this is the case oil will leak through the sensor and come out the connector end where the pins are-when you unplug it the connector will have oil on it (before you removed the engine-doubt you would see it now-after 4 blocks) Since you didnt backprobe it with a digital graphing multimeter or DSO before hand and it broke trying to remove it-finish replacing it and see how that works. You will not be able to push it in-the crank tone ring will prevent thisin 90% of cases. The dremel and wood screw is typically what i use (with a small vise grip and a prybar-slowly work it out while pushing in a little and pulling out-dont get excited-it's not sex! slow and steady!-spraying brake cleaner on the sensor area will help disolve the deposits), the reason it's not coming out is the portion of the sensor in the engine gets "coked" up with carbon deposits (very similar to that brownish deposit on a dipstick/oil fill cap) and makes the sensor to large to pull through the sensor hole-SLOW AND STEADY! Good luck! Regards, James Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted March 13, 2005 Report Share Posted March 13, 2005 I looked in AllData just now and from the exploded diagram it looks like the cam gear is all steel as oposed to a plastic gear over an aluminum base. (looked up a 90 3.1 NA) however it does state that you should use locktight on the bolt holding the gear to the cam. Is it possible you didnt locktight the cam bolt? then it may have been able to looses and fall off or shear the alignment pin on the cam. Def time to yank the Tchain cover off! James Quote Link to comment Share on other sites More sharing options...
TGPilot Posted March 13, 2005 Report Share Posted March 13, 2005 Def time to yank the Tchain cover off! James Well I hate to state the obvious...but that motor needs to come apart! I would start at the TC cover and see what came apart. Then pull the rear valve cover and entire intake. Look at each pushrod individually and roll them on a plate of thick flat glass to see if they are bent. Normally...but not always the pushrod will bend before a valve. You may have perfectly straight pushrods...but a valve is bent. You may have gotten lucky and the valves didn't kiss the piston hard enough to cause damage. Regardless the motor needs to be pulled apart to see what went wrong and why the rockers are not moving... 8) Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 Now Josh...if none of the rockers are moving then think. What makes the cam rotate? The chain connects the crank gear to the cam gear. You need to pull the front of the motor apart to see the components that make the cam go round and round. i will be pulling the plenum off and removing the rear valve cover very soon to check for rocker movement on the rear bank. i want to avoid pulling the LIM off if necessary but if i have to than so be it. i will pull the engine out of the car before i pull the timing cover off though. i've R&R'd the harmonic balancer on this engine *in* the car before and it was a kind of a PITA. pulling an engine & trans from a W-body is really pretty easy anyway. It could be the crank gear keyway is stripped out and free spinning, it could be the chain is busted, it could be the cam gear teeth are made of teflon (not sure what engines GM did that to) and they shattered, could be the cam shaft busted right at the cam gear bolts, or could be the cam broke down the shaft somewhere (not likely as you said none of the front bank rockers are moving). 8) we'll have to see after i check for rear bank valvetrain movement and weather any of the rear pushrods are bent....then go from there. either way the motor is going to be pulled and the timing cover will be removed. at this point i'm just hoping i don't have to pull the heads or LIM back off! Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 The dremel and wood screw is typically what i use (with a small vise grip and a prybar-slowly work it out while pushing in a little and pulling out-dont get excited-it's not sex! slow and steady!-spraying brake cleaner on the sensor area will help disolve the deposits), the reason it's not coming out is the portion of the sensor in the engine gets "coked" up with carbon deposits (very similar to that brownish deposit on a dipstick/oil fill cap) and makes the sensor to large to pull through the sensor hole-SLOW AND STEADY! Good luck! Regards, James thanks and that's exactly how i removed the old one! except i really couldn't get the wood screw in because it was so brittle it just kept breaking apart. i was finally able to break it up enough that i could pry it out with a long thin screwdriver. even though the CPS turned out not to be the problem, i feel better knowing a new one is in there now. Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 so is anyone 100% SURE that the 3.1 MPFI motor is or is not an interferance motor? Quote Link to comment Share on other sites More sharing options...
sl3196 Posted March 13, 2005 Report Share Posted March 13, 2005 :shock: Gillette Last Update on Mar 13, 10:55 am MST Partly Cloudy and Windy 33°F (1°C) Humidity: 66 % Wind Speed: NW 30 G 36 MPH Barometer: 30.01" (1018.9 mb) Dewpoint: 23°F (-5°C) Wind Chill: 19°F (-7°C) Visibility: 9.00 mi. More Local Wx: 2 Day History: Your crazy Josh! Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 I looked in AllData just now and from the exploded diagram it looks like the cam gear is all steel as oposed to a plastic gear over an aluminum base. (looked up a 90 3.1 NA) however it does state that you should use locktight on the bolt holding the gear to the cam.Is it possible you didnt locktight the cam bolt? then it may have been able to looses and fall off or shear the alignment pin on the cam. Def time to yank the Tchain cover off! James i'm actually working with a '91 NA 3.1 shortblock FWIW. i'm pretty sure it's all steel though. i've never had the timing chain removed....this engine has 227,000 miles on a completely unrebuilt shortblock (except new Melling HV oil pump). yes i'm crazy and i just learned the hard way that i should have done this the right way and not the budget way :oops: anyway it sounds more and more like i snapped the camshaft near the cam gear....i'll update soon. time for me to go out and get to work on the other car though! Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted March 13, 2005 Report Share Posted March 13, 2005 90% sure it isnt an interfearance engine-Alldata doesnt mention it and they do if it is an interference engine when telling you how to replace a Tbelt/Tchain I am really curious now as to what happened! Quote Link to comment Share on other sites More sharing options...
Jeorge Posted March 13, 2005 Report Share Posted March 13, 2005 well shit just get the GM preformance cam and do a 3100 top end swap if you have to pull it....and call it good...how ever you might want to pull the pan and do rings too if you did it that way...that way its all good to go..a complete inframe rebuild..LOL... anyways good luck if the cam is Broken there is a whole you can drill on the inner fender and you can pull the cam with out pulling the motor...I have seen on ClubGP i think where they have done that to save time...dont know if I recomend it or not or if its just the easy way out... also when you had that High milage motor out did you replace the Front and rear main seals? Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted March 13, 2005 Report Share Posted March 13, 2005 just did some more reasearch for ya and found this..... 91-95 3.4LDOHC is not an iterference engine it is identified as a freewheeling type 96+ 3.4 DOHC is however identified as an Interference engine (valve to piston dmage is MOST LIKELY to occur) I really doubt you kissed any valves at this point maybe if you had put in an aftermarket cam...but not factory I cant find a single reference to the 91 3.1L being an interference engine nor can i find any TSB's on cam failure or what not Time to yank her apart! Regards, James Quote Link to comment Share on other sites More sharing options...
TGPilot Posted March 13, 2005 Report Share Posted March 13, 2005 i've never had the timing chain removed....this engine has 227,000 miles on a completely unrebuilt shortblock Ok...should we start a betting pool as to what happened? 227k miles...Timing Chain! $20 8) Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted March 13, 2005 Report Share Posted March 13, 2005 AWE! you already got that! dam alright i call T chain link went bad/broke! Quote Link to comment Share on other sites More sharing options...
sl3196 Posted March 13, 2005 Report Share Posted March 13, 2005 i've never had the timing chain removed....this engine has 227,000 miles on a completely unrebuilt shortblock Ok...should we start a betting pool as to what happened? 227k miles...Timing Chain! $20 8) Shit! Quote Link to comment Share on other sites More sharing options...
HokemBokem Posted March 13, 2005 Report Share Posted March 13, 2005 i've never had the timing chain removed....this engine has 227,000 miles on a completely unrebuilt shortblock Ok...should we start a betting pool as to what happened? 227k miles...Timing Chain! $20 8) That sucks so bad that this happened right before Dyno day. Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 :shock: Gillette Last Update on Mar 13, 10:55 am MST Partly Cloudy and Windy 33°F (1°C) Humidity: 66 % Wind Speed: NW 30 G 36 MPH Barometer: 30.01" (1018.9 mb) Dewpoint: 23°F (-5°C) Wind Chill: 19°F (-7°C) Visibility: 9.00 mi. More Local Wx: 2 Day History: Your crazy Josh! iTurbo and i just now got done pulling the T2/A555 out of my GTS it's now in my garage. we are going to try to unbolt the bad A555 from the trans and slip the good A555 & bolt it up by the time Jerm goes to work at 5pm at least we can work in the garage now. the GTS should be back to daily driver status tomarrow. woot! and yeah it was cold! laying on my back in a wet parking lot at 30* outside temp isn't my favorite activity :? but we made tons of progress! Quote Link to comment Share on other sites More sharing options...
sl3196 Posted March 13, 2005 Report Share Posted March 13, 2005 Damn your fast! :shock: How you liking this on/off snow crap? Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 well shit just get the GM preformance cam and do a 3100 top end swap if you have to pull it....and call it good...how ever you might want to pull the pan and do rings too if you did it that way...that way its all good to go..a complete inframe rebuild..LOL... nah i'm not putting that much work into this turbocharged VIN 'T' engine. if i did i would start with the blown TGP 'V' motor i have in my garage. i don't want to mess around with building a custom crossover or the rear manifold issue associated with a turbo 3x00 either. anyways good luck if the cam is Broken there is a whole you can drill on the inner fender and you can pull the cam with out pulling the motor...I have seen on ClubGP i think where they have done that to save time...dont know if I recomend it or not or if its just the easy way out... also when you had that High milage motor out did you replace the Front and rear main seals? i'll be pulling the motor completely out so i can work on it easier in my garage (with a portable heater lol). i replaced both the front and rear main seals (as well as every single other gasket & seal you can think of) within the past few weeks. if the cam is broken i'll probably go with a stock GM cam...i haven't thought about it that much yet. all the lobes on the cam looked good before i put the LIM on this engine. hopefully the timing chain broke and not the camshaft. Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted March 13, 2005 Report Share Posted March 13, 2005 That sucks so bad that this happened right before Dyno day. oh man i honestly hope the 3.1 MPFI is a non-interferance engine and all i have to do is swap in a new timing chain set! if that was all it was i could probably make it to dyno day with it (either way, i'll have my GTS ready to go if the Cutlass can't make it). replacing a timing chain looks like it would be easy enough.... Quote Link to comment Share on other sites More sharing options...
GP1138 Posted March 13, 2005 Report Share Posted March 13, 2005 After spending about an hour alone on getting heads aligned and exhaust manifolds (maybe more than an hour...) I have a new respect for anyone that's ever done this.... my hands fucking hurt right now. Quote Link to comment Share on other sites More sharing options...
HokemBokem Posted March 13, 2005 Report Share Posted March 13, 2005 That sucks so bad that this happened right before Dyno day. oh man i honestly hope the 3.1 MPFI is a non-interferance engine and all i have to do is swap in a new timing chain set! if that was all it was i could probably make it to dyno day with it (either way, i'll have my GTS ready to go if the Cutlass can't make it). replacing a timing chain looks like it would be easy enough.... Yea that would be nice. I hope the Cutty can make it! Quote Link to comment Share on other sites More sharing options...
Prospeeder Posted March 14, 2005 Report Share Posted March 14, 2005 oh, so u have a regular 3.1 mpfi with the turbo and i/c on it and the plenum or an actualy TGP motor?? Quote Link to comment Share on other sites More sharing options...
R Dubya Posted March 14, 2005 Report Share Posted March 14, 2005 It is a motor out of a plain 'ol GP.. a 3.1 Vin code 'T' engine. The vin code 'V' is the turbo code. There a few differences in the 'T' and 'V' engines. Mainly pistons, crankshaft and oil pump. But he built it to be a 3.1 'V', just without changing the pistons. This sucks to hear Josh, it sounded good on that video, too bad things work out like they do sometimes. I had problems with my TGP engine last year, I actually had a lost cam lobe that resulted in a teardown/rebuild. I feel your pain. Quote Link to comment Share on other sites More sharing options...
Canada Posted March 14, 2005 Report Share Posted March 14, 2005 I think its a good idea to pull the motor out again.....since this is somewhat of a high performance motor. Quote Link to comment Share on other sites More sharing options...
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