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oiling system 3.1L V6 1998 chevy malibu


rocketmanfxr
07-29-2012, 02:42 PM
I have a 1998 chevy malibu with a 3.1L V6 in it. I recently purchased it and was told the oil pump was bad. The car would only start and run for 5 seconds or so and the lifters were rateling BAD. So I droped the oil pan and inspected the oil pump and there wasnt any signs of excessive wear, groves from metal ,etc etc. I then put the drive shaft up into the engine and had someone turn the engine over. Sucess! the shaft did not turn. Therefore I came to the conclusion that the camshaft was broken. Because with the valve cover off only one or two of the valves were opening. But this could have been due to no oil pressure. After tearing the top end apart to look at the cam I removed the oil pump drive gear and when I put my finger down on the camshaft oil pump drive gear it spun freely. my question is this. How is that gear attached to the cam? Is it a press fit? or is it on a woodruff key?

maxwedge
07-29-2012, 03:17 PM
Even with the lifters collapsed the would be some valve movement, check this further.

rocketmanfxr
07-29-2012, 04:00 PM
Yes, there was SOME movement of one or two of the valve springs, but not all of them across the board. There is NO DOUBT in my mind that the camshaft IS NOT broken and that it is mearly the drive gear an the camshaft that is the problem. Once again, I ask, how is that gear attached to the camshaft? Press fit onto the camshaft, or keyed?

aleekat
07-29-2012, 04:43 PM
Hoping it's not the camshaft but. Have a 95 cutlass with the exact same motor. Had noise, shut it down. Had a mechanic friend come get it and first thought was oil pump. Then found the broken camshaft at the rear area. Replaced it with a motor out of 98 malibu. He called around when looking for a motor that this was a common problem. Had only 116k on that motor. Good luck.

Blue Bowtie
07-29-2012, 05:56 PM
Here are just a few examples of the symptoms, and the reported results (broken camshafts):

www.automotiveforums.com/vbulletin/showthread.php?t=402930

www.automotiveforums.com/vbulletin/showthread.php?t=689273

www.automotiveforums.com/vbulletin/showthread.php?t=407222

www.automotiveforums.com/vbulletin/showthread.php?t=900759

www.automotiveforums.com/vbulletin/showthread.php?t=945577

www.automotiveforums.com/vbulletin/showthread.php?t=1078224

rocketmanfxr
07-30-2012, 06:41 AM
I must apologize to everyone. After further and closer inspection, I found that the camshaft WAS broken on my 1998 malibu. It was broken at the back of the camshaft very close to the gear that drives the oil pump drive gear. (that sounds like a lot of gears driving a lot of other gears) Now for the hard part, changing the camshaft!! BUT, problem solved. I wish to thank everyone involved in trying to help me and give me information. I hope I can some how return the favor for someone else in the future.

Blue Bowtie
07-30-2012, 10:18 PM
No apologies necessary. I wish it were something else - something less difficult. The camshaft replacement and probable other repairs from running with no oil pressure are no small task in the vehicle.

If the vehicle is in good condition otherwise, you might shop a bit for a lower mileage used engine/trans and perform the swap. You'll likely have to at least raise the engine or drop the entire cradle from under the front end in order to gain access to the timing cover and everything you would need to change the cam. Between a cam, oil pump, cam bearing set, main and rod bearing set (and possibly a reground crank kit), timing sprockets and chain, gaskets, and all the other bits and pieces you would need it may be worth a quick look through your local/regional wrecking yards for a good used assembly with some form of guaranty (it's not that unusual).

You can probably find a reman long block with a 5/50 warranty for under $1500, but you might be able to find a replacement '98 for about that price.

Good luck. I hope it goes well.

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