I think I killed the 2.8 in Fierfly's 85 GT. I was doing a run through some curves to test a new camera mount when it went. Here are the videos.

The tapping that remains constant in this video is an issue with the camera mount...but you will see when it happens, and can hopefully separate the mount noises from the engine noises. For the record, the oil gauge works intermittently, but when working it would read around 50psi, rising when the RPMs are higher. Oil level was fine before and after this run.


This is the confirmation once I limped it back home.



The higher the RPM, the worse it would get. It would stall when I would push in the clutch, but would start right back up. The knocking is worse when free revving than when it is accelerating.

Doesn't really matter which part broke at this point...I assume it needs to be either completely rebuilt or replaced. What are our options?
It will be replaced with a 60 degree V6...I am still doing a 3800 swap in my car, I am not into doing something that extreme here. So...here are my thoughts at the moment.

Camaro 3.4 liter. This is an almost direct replacement of the long block using the rest of the parts from the Fiero. To complete this, we need the starter jig from RD, a neutrally balanced flywheel...and possibly an 88 oil pan, timing cover (and harmonic balancer?). I have the 88 parts other than the flywheel. Am I missing anything here? I would probably choose to drop in a 7730 ECU at the same time.

Later 3400, 3500, 3900? For this, I need the flywheel still, and would replace the intake also. Does the Fiero exhaust manifolds bolt up to these, or do I need to run a new exhaust? Wiring does not scare me much...I can handle that...but I don't want to get to much into making custom parts. It is my understanding that I could put the oil pan and timing cover from the 88 on this and then use the Fiero accessories....or stick with the newer accessories. I can use the 7730 ecu for these, right? What about the engine mount...will the stock engine mount still work on this?

We are also considering a transmission upgrade at the same time....either to a 5 speed or to a 4 speed auto. If we find a getrag, I have the mounts, shifter and possibly the cables. If we switched to an auto, I would get the auto that comes with the newer engine (meaning we only go auto if we go with one of the newer series of engines). This would mean new mounts (ugh), and some shifter work....plus new axles....hmmm....the change to an auto is looking to be more difficult. Would the Isuzu 5 speed hold up to the power of the 3.4 or the newer ones? I can drive it smooth....but Fierfly is still a newbie at driving a manual.

Shhhhh....don't tell Fierfly....I haven't broken the news to her yet.

Is the tach accurate? You were buzzing it pretty high. I see the oil light come on and off several times. You know it works off a different section of the sending unit than the gauge? Since it was coming on, I assume you lost oil pressure even though the gauge shows it's okay. I agree with your assessment, sounds like severe rod knock and a rebuild is in order.

[This message has been edited by Formula350 (edited 01-14-2010).]

Oh No! now that stinks!
bring it to me I can re build it or swap it if need be or you want to eather way let me know if I can help.
D.

The 3.4l pushrod is very underrated. I have one with some light performance work and a Trueleo intake and I am completely confident I could beat out a 3800 N/A in a race. It's cheap as hell and easy, too.

quote Originally posted by Formula350: Is the tach accurate? You were buzzing it pretty high. I see the oil light come on and off several times. You know it works off a different section of the sending unit than the gauge? Since it was coming on, I assume you lost oil pressure even though the gauge shows it's okay. I agree with your assessment, sounds like severe rod knock and a rebuild is in order.

Tach reads 400rpm high...but regardless, I wasn't babying it. You sure you aren't seeing the Voltage light rather than the Oil light? I went back and watched it again and only see the voltage light coming on. But...in the end, that detail is irrelevant.

It sounds like my firebird did when it spun a bearing. Might want to check that out.

Yeah, thats a spun bearing. I drove with one about 30 miles one morning. It was making so much gawd awful racket by the time I got it home. I babied it the whole way. I found too that it was quietest under load, or if I just let it idle. The worst noise was when you let off the throttle at moderate RPM in gear. It made it home! I snagged a 3.4 Camaro motor that day and was driving the car again in 3 days.

I damaged the motor when I was coming around a sweeping right turn pulling full G's, top of second gear, near 5K. The motor had a light tap after that. It lasted 2 weeks before the bearing finally spun on the way to work one morning.

Sorry about the motor.

The 3100-3400-3500-3900 series engines are not the easiest to swap. They all require you to go with DIS, rewire, and use a different ECM, Your brackets and accessories will not fit very well. However, I have heard of people swapping the waterpump, and timing cover to these engines from the Fiero, and making an adaptor plate to mount to the heads. The Fiero's intake will not fit, no way no how. The exhaust doesn't really fit well either. You can slot the manifolds to fit the studs, but the exhaust ports are much bigger on the engine then on the Fiero's manifolds. So really, they are a waste. The exhaust studs are further apart on the 3.1 series aluminum heads then the cast iron ones. You cannot use Fiero heads on these engines unless you change the pistons either. Otherwise you wind up with VERY low compression.
However, They perform very well, provide Excellent gas mileage, can take one huge beating. And if they break, parts are extremely cheep and abundant. The Camaro 3.4L, is just a 2.8 with slightly more low end punch. With the Fiero computer, it is ok. But it has no real advantages over the 2.8. It shines a bit more with DIS and a 7730. The Fiero's computer and intake manifold don't bring out the engines potential very well at all. But its easy to do.

quote Originally posted by CowsPatoot: You sure you aren't seeing the Voltage light rather than the Oil light? I went back and watched it again and only see the voltage light coming on. But...in the end, that detail is irrelevant.

Sorry, it's been so long since I've actually driven my Fiero I don't remember which light is in what gauge.

How many miles on the engine? I have seen many 85 V6s that just don't make it much past 110K. You may want to opt for the 3.4L swap.

Yea thats a rod bearing, probably spun. If you catch it soon enough you can slip a new bearing in, but its always a gamble at that point. Still for $5 and couple hours work, its worth a shot.

quote Originally posted by jaskispyder: How many miles on the engine? I have seen many 85 V6s that just don't make it much past 110K. You may want to opt for the 3.4L swap.

We aren't sure how many miles it has on it. It was purchased in June, PO claimed it had 80k on it (car had 193k). I seriously doubt it was new when he put it in, so even if it was only 80k on that engine, it is still a 25 year old engine. Fierfly and I pretty much decided on upgrading to the 3400 with a 7730 computer...and probably sticking with the 4 speed manual. But.....

quote Originally posted by 86GT3.4DOHC: Yea thats a rod bearing, probably spun. If you catch it soon enough you can slip a new bearing in, but its always a gamble at that point. Still for $5 and couple hours work, its worth a shot.

That is a good point....and I am quite sure I caught it early enough. All I have to remove is the oil pan to do that, right? I think I can live with the risk in that gamble considering how tight money is right now. Worst case scenario I lost a couple hours work and a combo meal at McDonalds....and I am willing to bet that the new bearing would last longer than the combo meal. More likely, it gives us the ability to drive the car while we collect parts for the ideal swap rather than just throwing the first thing that comes along in there.

Hmmm....should I replace all 6 of them while I am in there? If one went, the others are likely not far behind.

Also... don't drive to the redline

These are not high revving engines.... they like the lower rpms... that is where the torque and power is produced in the GM engines of those years. Plus the 85s had oil passage issues, so high revs are not good.

J.

Had the same fun experience earlier with my 2.8. You have to take off the starter to get to all of the oil pan bolts first.

Be sure to check all of the rods, not just the first one that feels loose. Had a few that felt loose, but it was cyl no. 4 that was spun. Replaced that bearing only to hear it knocking as soon as it started. Hope you caught it soon enough!

Sorry to say, you most likely killed the bottom end. New crank etc time or new block/engine. BTW: with a stock intake don't bother reving over 5k, no power up there. BTW: the 2.8 - 3.4s can rev high, make good power, and live, just not in stock trim.

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