finding myself in new territory

[3100 MPFI]

okay. So I just bought another W-body. This time it is a 1995 Cutlass Supreme SL coupe with the 3.4 DOHC. It needs some help, so I know this is where to go to get it.

First of all, when I bought it, the seller said the engine was KNOCKING, but when we started it to get it to my house, it was NOT knocking. If this was a PUSHROD engine, I would say it was a VERY BAD lifter tick.

It was hard to start (I found out the battery is not strong enough, and am getting a new one).

Once it was started, I had to keep my foot on the gas so that it would not die. It had a misfire pretty bad, but that seemed to clear up SOME as I was driving it home (home was only 3 miles away).




Tomorrow, I am going to get new plugs, and wires, and gaskets for the upper, and lower intake manifolds. A friend suggested I try changing out my EGR (he had a similar running issue, and his EGR was stuck open, so I will stick my spare one on there from the 3100). I am also going to check the timing to be sure it is set right. The belt looks good, so I don't want to replace it if it is not needed just yet.



Can anyone else think of anything else I should check? Keep in mind that I know the basics because of my work with the 3100, and 3.1 in my other 3 w-bodies. This is the first time I am working on a 3.4 DOHC of my own.

[SappySE107]

I think you got everything listed that you should check. Id replace the O2 if its unknown condition. Its possible that a lifter has gone bad though. Do a compression test.

[3100 MPFI]

well, it is worse that I hoped.

First of all, there was a LOT wrong with it to begine with. I found that both the upper, and lower intake gaskets were leaking, the EGR was stuck open, and several of the vacuum lines were broken.

The timing was actually correct, and the belt looks fairly new, but when I removed the spark plugs (bosch platinum), number 3 had no insulator at all. The spark plug wires were also old.

It also had a battery that was too weak to start the car (it was under 500 CCA).

Well, I got it all put back together, and it was a bitch to start, but once it did, it settled into a good steady idle fairly fast, BUT when i raise the RPM's, it starts knocking. I am going to do an oil change on it still, but it looks like I have to pull it and replace the crank anyways.

Still, for $300, and $100 in parts, I am still happy in the whole deal.

[timg]

These motors can have fairly severe lifter tick. Make sure that isn't what you're hearing before tearing into it. I have some videos of my Monte on Google videos with some fairly loud lifter tick if you need something to compare it with. Search for turbo Monte videos.

Tim

[Timothy]

Cam Timing

Verify Cam timing, one tooth off or more
using the match mark method and I've heard awful noises out of these dohc!!!

[3100 MPFI]

I have heard a knock before, and this is a knock. I know the differance. I also checked the timing, and it is 100% correct. This is a definant knock.

Also, the crank is REALLY hard to turn by hand (using a breaker bar, I can barely move it). The crank is not suppose to be this difficult to turn, so I am thinking it has a spun bearing.

[93Oldsdroptop]

Bosch platinum plugs? Get them OUT of there and get some Delco Rapidfire 8's. Or just stock AC/Delcos if you prefer. Our engines do not like Bosch plugs. You will notice an immediate difference.

Sounds like you have most of the other stuff covered, good luck with it.

[GTP091]

These motors can have fairly severe lifter tick. Make sure that isn't what you're hearing before tearing into it. I have some videos of my Monte on Google videos with some fairly loud lifter tick if you need something to compare it with. Search for turbo Monte videos.

Tim

What type of system are you running for your exhaust???

[DarksideGA]

what did u have to do/pay to get that lifter fixed on the monty

[dohcfiend]

also replace the fuel filter if condition is unknown. oh if for any reason you have to remove the rear head, replace the o-ring on the dist plug. if it is leaking now, just pull it up a little and use some liquid gasket to fix it.

i am sure u know this already but if the crank needs replacing. a dohc 3.4 uses the same crank as a 3.1/3.4 pushrod as long as the engine they came out of uses the 3-coilpack dis system.

[craftsman_454]

if your sure its a bottom end knock(which is common) theres only one other way i can think off to diagnose it without rippin the crank out. take off the timing belt and see if the crank is still hard to turn. check each cam as well.

[grandprixgtp_91]

these 3.4L DOHC's are very hard to turn over compared to the other 60* engines, so dont go by that, usually if its a bottom end knock it will do it all the time and your oil pressure will be zero at idle, just keep that in mind, and usually a bottom end knock is very very loud. these motors make alot of different noises that sound like bottom end but isnt.

Jake