It is to my dismay that I think my '85 GT has spun a bearing and now has knock. Can someone confirm I am correct in this? I have never heard rod knock before, so I am only assuming.
Hi, It sounds like valve train noise to me. Take out the valve cover breather and see if the noise gets louder. How is your oil pressure? Cheers.
I'm currently out of town, but I will. research and do that tomorrow. Please excuse my ignorance, but this car is my first project car and Im not exactly. sure what the valve cover breather is. Is it the hose that connects into the valve cover to the right of the oil cap?
Hello Jared! Your suspisions are right, it is a rod knock. The sound matches RPM speed, if it was valvetrain noise it would be half the speed of the engine, in other words the knocking would sound slower. You can check it by running the engine for 2 minutes and shot engine off and pull the oil dipstick. Take a light and shine it to the dipstick, if you see little sparkles of light that is you bearing in pieces. You can also drain the oil and do the same test with the light. Good luck!
Hello Jared! Your suspisions are right, it is a rod knock. The sound matches RPM speed, if it was valvetrain noise it would be half the speed of the engine, in other words the knocking would sound slower. You can check it by running the engine for 2 minutes and shot engine off and pull the oil dipstick. Take a light and shine it to the dipstick, if you see little sparkles of light that is you bearing in pieces. You can also drain the oil and do the same test with the light. Good luck!
Rei
Thank you for the response. Just another question - I watched videos of other Fiero V6s with rod knock, and theirs sounded a lot more harsh than mine. Is there a reason and. still the slightest possibility that my engine isn't toast?
It's difficult to tell for sure listening to a video... but I'd guess it's a rod knocking.
Be honest now, for diagnostic purposes. (We're not judging you.) What was your oil level at, and what were you doing prior to the knock starting? Were you revving the engine high... and/or were you taking a tight corner at speed?
It's difficult to tell for sure listening to a video... but I'd guess it's a rod knocking.
Be honest now, for diagnostic purposes. (We're not judging you.) What was your oil level at, and what were you doing prior to the knock starting? Were you revving the engine high... and/or were you taking a tight corner at speed?
Driving in a straight line, oil was at the correct level, but it was due for an oil change (about 100 miles over.) Was going straight from a stoplight, put it in first and started to go forward, pushed my foot in on the clutch, and the car continued to rev even without the gas pedal being touched. From what I assume, the throttle body stayed open. RPMS shot to redline, I immediately turned off the car and coasted in neutral to the side of the road, went to the back of the car and manually shut the throttle body before turning the car back on again. That was what I had heard after that. The BrakeMax was only a quarter mile down the road, so I drove it over there and had them change the oil. They didn't say anything seemed wrong. I was watching them do the oil change, and afterwards, they couldnt figure out how to get it into reverse. They slammed it over a few times and flashed the brake lights (It was making me cringe the whole time) and finally they got it into reverse and parked it. Now it refuses to be put into reverse.
...put it in first and started to go forward, pushed my foot in on the clutch, and the car continued to rev even without the gas pedal being touched. From what I assume, the throttle body stayed open. RPMS shot to redline, I immediately turned off the car and coasted in neutral to the side of the road, went to the back of the car and manually shut the throttle body...
...
How long have you had and/or been driving this car?
b) why you would take it out of gear and allow the engine to increase revs without any load on the engine
a) The throttle originally didn't open by itself. I was starting from a dead stop in first gear. Pushed my foot in on the clutch to shift at about 3K rpm, but it kept climbing.
b) I took it out of first gear to shift to second. After the engine kept revving up to 5500+, I turned off the car because I didn't know what else to do
Definitely the sound of a "ROD KNOCKING" as the result of a bearing worn so thin that it lost its captivity. Those are 2 words you never want to hear in the same sentence however this is just a mild introduction to disaster meaning you can at least still here the rod. The next phase would be "Throwing a Rod". Although you'd no longer here the knocking rod you'd be worst off especially if the rod was thrown on the down-stroke and sailed thru the block meaning no chance for an engine rebuild ever! Now you have to make a big decision. Rebuild or replace? I would replace instead of rebuilding. Check the link below. These fellows decided to rebuild resulting in a sunken heart with all family members present to watch the humiliation.
PS: A friend of mine (manager of the body shop that painted my Fiero) had his boat engine rebuilt twice and twice it spun a bearing the same year. Of course this sort of thing never happens on dry land so he was virtually a sitting duck at sea both times.
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
while you have the engine out, Don't put another 2.8 back in. put in a 3.4, same amount of work, easier to find and more power.
I don't have any knowledge on the 3.4 engine. I don't know what other cars to find it in, I don't know about the swap, and I don't know how expensive it will be. Can you enlighten me?
Is it basically just a swap that I can use the same harness in? Do I have to fabricate new mounts and other things? I appreciate the help and I don't know where to look for better details.
Use the search function or look on the second page of the construction zone for 3.4L. Pushrods swap the author is sardonyx247. The page has a lot pictures and information on small details.
I don't have any knowledge on the 3.4 engine. I don't know what other cars to find it in, I don't know about the swap, and I don't know how expensive it will be. Can you enlighten me?
Is it basically just a swap that I can use the same harness in? Do I have to fabricate new mounts and other things? I appreciate the help and I don't know where to look for better details.
The 3.4L pushrod engine found in 93-95 Camaros and Firebirds is as close to a direct bolt in as you will find. It looks nearly identical to the Fiero 2.8L. Just drill and tap two holes for the starter, (Rodney sells the jig) bolt on the Fiero 2.8L timing chain cover, distributor, water pump, manifolds, fuel rail and on some years the oil pan. The engine attaches to the Fiero mounts uses the same harness and ECM. Anyone who can replace an engine can do the 3.4L swap. IMO. two or three days work but very easy.
[This message has been edited by Dennis LaGrua (edited 11-27-2018).]
