1999 3.4l HO broken camshaft [Archive] - GrandAmGT.com Forum


View Full Version : 1999 3.4l HO broken camshaft

09-25-2013, 01:04 PM
Hi i am posting this on behalf of my sister so i may not have all the information, but here goes. She lent her car to our other sister and while she was driving it some how she broke the cam shaft, the torque convertor lockup has been acting weird for a while now, what i am wondering is if it was unlocking and re locking then my sister kicked it down would the flex cause the cam to break in half? Second question The "HO" badging on the fender is that just there because of the Ram air intake? Thirdly if i had a motor out of an Alero could the intake off of the GA be put on a LA1 3.4 and retain the ram air, if that is all that makes it the HO version of the motor? 4th the GM dealer said that the HO had a bigger camshaft then the regular 3.4 is that true or hot air from the dealer?

Any input would be appreciated

09-25-2013, 01:27 PM
It is doubtful that the torque converter issue caused the camshaft to break.
The camshaft is hollow and while rare, there have been a few reports of them breaking in older motors.
The "HO" badging is mainly cosmetic, as most people accept that the "Ram Air" is more gimmicky than anything.
Yes, you can swap in an Alero motor and keep the Ram Air. Only the bottom half of the airbox is different.
The dealer is full of hot air; all 3400 V6 motors used the same camshaft specs. The trigger for the camshaft position sensor did change over the years though.

09-25-2013, 01:54 PM
Yep, exactly as Matt said. TC lockup would not cause an stress on the engine to reach the cam shaft, as it's not connected to the cam by anything solid. They factory cams are kind of weak, and while not usual, there have been a few instances of them cracking. If the cam does break though, there are often other things in the engine that get messed up (bent valves, dinged pistons, etc) so make sure you have the engine thoroughly checked if you have it repaired.

Whether you do, or just replace it with another engine, you can do a couple things to make sure it doesn't happen again, and to avoid other problems. Sealed power makes an OEM spec cam shaft that is solid instead of hollow that is much more durable. Also I'd replace the lower intake gaskets with the premium set from fel-pro. That will avoid the common lim gasket leaks they get.

The H.O. was just the badged they put on the car for '99 because they got a few more hp out of the 3400 in the grand am that year and wanted to call it "high output". It was mainly due to the intake and exhaust design. The cam shafts are all the same in all years of 3400. Later in 2000 and up they changed the badge to "ram air". There was no difference in the camshaft. In 2000 they changed the upper intake manifold design (slight change in the neck inlet, and the EGR valve inlet), the fuel injectors, cam position sensor, and a few other minor things. Most of your engine controls will swap directly over to a newer 3400 though. Basically you could use any 3400 from 96-05 with only minor adaptations.

09-25-2013, 08:11 PM
Thank you for the information, It sure helps a lot.

09-25-2013, 08:16 PM
tradce for ls1?

09-25-2013, 08:18 PM
someone hit the sauce tonight lol

09-25-2013, 08:18 PM
nug uhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh cant oroive it

09-25-2013, 08:43 PM
Inspect the cam bearings. It's likely at least one of them has spun in the boar meaning the block is toast. Not to mention a broken camshaft would cause the oil pump to stop spinning since it is driven by the camshaft.

Your best bet at this point is to get a new engine entirely.

H.O. Driver
09-26-2013, 07:21 PM
Your best bet is finding a donor car that was rear ended in a scrap yard some where. There are lots of vehicles up north here that have the 3.4l in them. You can always salvage some sensors and things to make it work. Just check block codes and VIN #s first so you don't have lots of headaches later. Just like the others said little things have changed over the years and models.

09-26-2013, 08:19 PM
This has 3500 swap written all over it! :angel

09-26-2013, 08:28 PM
That's what i was thinking, By the way If you were looking at the engine from in front of the car which side is the oil pump driven on? A 3500 swap is kinda out of our price range right now:(

09-26-2013, 08:55 PM
That's what i was thinking, By the way If you were looking at the engine from in front of the car which side is the oil pump driven on? A 3500 swap is kinda out of our price range right now:(

It's not really that much cost wise. You can get a good used 3500 engine for around $450 plus the swap kit for just doing a basic swap.

The oil pump drive shaft is right below the cross-over pipe and T-Stat area...it's a small round metal thing with a hold down bracket and one bolt. You can see it right behind the T-Stat housing to the right side in this picture:

http://i10.photobucket.com/albums/a138/Starglow/DSCF0790_zpsa5d2a547.jpg (http://s10.photobucket.com/user/Starglow/media/DSCF0790_zpsa5d2a547.jpg.html)