Bent pushrods on '97 GTS

[Martin]

I was out driving yesterday and, after a redline 1-2 shift, I heard a loud clacking coming from the engine. I shut down immediately and went to look for anything obvious like a belt that was shredding or a dent in a valve cover from a pushrod coming out of its cup - but everything looked OK. I started back up, let it idle, and could clearly hear a clacking that sounded like it was happening once every revolution. Since the car seemed to idle OK, I limped it home in high gear - fortunately I was only a mile from home at that point.

When I took one of the valve covers off, it's clear that a couple of exhaust side pushrods are VERY bent.

The car is mostly stock, and has less than 10K on it.

The question is this - in your experience when you've seen bent pushrods, is it likely that there are some really big problems going on internally? For example, is the cam likely toast at that point, or are the valves/pistons damaged? Every time I've seen bent pushrods in the past it's been due to piston-valve contact, and I'm totally perplexed as to how that could happen with this car - it has the stock rockers, and I'm assuming there should be plenty of clearance.

I'm keeping my fingers crossed that this is something that people have seen a bunch of times before with these engines and it's not as bad as my gut is telling me. I was about to go with new Mopar rockers and pushrods anyway, so I'm hopeful that I can just do the swap and everything will be great again - but again my gut tells me that I'm headed for a big repair job here.

Thanks in advance!
Martin

 

[crazyspeed]

Martin Martin. A true enthusiast is happy when something breaks.. think of it as a greatr opportunity for more mods
Now's your chance to go with the Striker heads and Jesel rockers...and don't forget to report back to us on your awesome upgrades.

 

[big-n-italian]

a bent push rod was also found in my '97 last year.

 

[Martin]

Martin Martin. A true enthusiast is happy when something breaks.. think of it as a greatr opportunity for more mods
Now's your chance to go with the Striker heads and Jesel rockers...and don't forget to report back to us on your awesome upgrades.

True - that's what I was thinking, too. I just hope nothing really important broke - those pushrods were pretty much all over the place and I'm hoping the cam doesn't need to come out. If it was valve float, that was some serious float! I'm bummed mostly because I've had this car since the day it was born - an unbelievable ten years now. I went ten years without a single problem, and the last two times I've driven it, it's had two reasonably significant failures. The first was when I grenaded the power steering pump, and now the pushrods. Ironically, I was out on a test drive to make sure the power steering pump was working right when the pushrods went south on me.

 

[Martin]

a bent push rod was also found in my '97 last year.

Was the pushrod just barely bent, or did it really bite into the guides? Also, did anything else happen as a result?

I'm thinking that I probably bent the pushrods a little bit a while back, and they just finally gave up the ghost during the last drive. It's one of those things that looks like it can happen and, if the car isn't really driven hard, won't cause a catastrophic failure. Those pushrod guides look like they give the pushrods all kinds of room and the only time they 'guide' anything is when the pushrods are bent all to heck.

 

[crazyspeed]

OK...now you guys are scaring me....cause I also have a 97 GTS. There has to be a known root cause. Can you do a search on this site? Also, I would ask Tony or the Wizard for input.
I would say that the valvesprings are suspect. Also the lifters are suspect. It's unlikely that the cam would be the root cause...but may sustain damage if a lifter jammed.
1) It's noteworthy that there is damage to more than one pushrod...makes me think valve springs cracked or weak.
2) How many pushrods are damaged?
3) How many miles on the engine?
4) At what rpm were you shifting?
5) Are you a hard driver? Have you over-reved in the past or missed a shift?
6) In the past...do you remember ever winding out to redline in third and then missed the shift into fourth?.....going into 2nd gear by mistake resuling in a really bad over-rev?
7) In order to minimize damage... never drive with a noise...even a short distance. Maybe we should all get a tow hook to keep in the car?

I'm just trying to help determine the root cause of your engine damage


I'm sorry you had this happen and I am sure you will get help here...this is board is a great resource and there are many willing to guide you. Please keep us up to date on this.

BTW If it happened to me, I would definitely want to remove the head/heads for a thorough inspection

 

[big-n-italian]

OK...now you guys are scaring me....cause I also have a 97 GTS. There has to be a known root cause. Can you do a search on this site? Also, I would ask Tony or the Wizard for input.
I would say that the valvesprings are suspect. Also the lifters are suspect. It's unlikely that the cam would be the root cause...but may sustain damage if a lifter jammed.
1) It's noteworthy that there is damage to more than one pushrod...makes me think valve springs cracked or weak.
2) How many pushrods are damaged?
3) How many miles on the engine?
4) At what rpm were you shifting?
5) Are you a hard driver? Have you over-reved in the past or missed a shift?
6) In the past...do you remember ever winding out to redline in third and then missed the shift into fourth?.....going into 2nd gear by mistake resuling in a really bad over-rev?
7) In order to minimize damage... never drive with a noise...even a short distance. Maybe we should all get a tow hook to keep in the car?

I'm just trying to help determine the root cause of your engine damage


I'm sorry you had this happen and I am sure you will get help here...this is board is a great resource and there are many willing to guide you. Please keep us up to date on this.

BTW If it happened to me, I would definitely want to remove the head/heads for a thorough inspection

we only found one in my car. i didnt hear it, but the tech heard it right away. i cant answer your other questions because i bought the car used. i think it happened before me partly because i dont drive very hard or ever redline the motor.

i wouldnt worry about it unless you live in New York. bent push rods always seem to happen to people who drive their 97 GTS's in NY.

 

[Martin]

I was talking to the guys over at Valaya Racing, and this isn't something that they've seen before in a car that hasn't experienced any missed shifts (at least none that I can remember over the past ten years). It has been driven pretty hard, though, and has experienced a lot of redline shifts. I've never bumped up against the rev limiter, though - so technically I don't think it should have ever been over revved. I'm guessing that the pushrods got bent a little bit somewhere along the line, and during the drive the other day they just gave up.

The engine only has around 10k on it, so it's still really fresh by normal standards. I'm going to have the guys at Valaya take it apart and see what's up, and I'll let everyone know what they find.

 

[Jack B]

I was talking to the guys over at Valaya Racing, and this isn't something that they've seen before in a car that hasn't experienced any missed shifts (at least none that I can remember over the past ten years). It has been driven pretty hard, though, and has experienced a lot of redline shifts. I've never bumped up against the rev limiter, though - so technically I don't think it should have ever been over revved. I'm guessing that the pushrods got bent a little bit somewhere along the line, and during the drive the other day they just gave up.

The engine only has around 10k on it, so it's still really fresh by normal standards. I'm going to have the guys at Valaya take it apart and see what's up, and I'll let everyone know what they find.

The viper valve train is one of its weak areas. The rev limiter keeps you under 6200 when on the throttle, but, the engine with float past that point after the limiter actuates. It is very possible to float the valves because of the oem springs and the stamped rockers. Another issue could be if you went from third to second, thinking it was fourth, the mass of the car would drive the engine way past 6200.

 

[Martin]

With it in mind that the valvetrain is a weak area, what are the suggestions to beef it up so that things like this don't happen again?

I'm definitely not a pro driver, but I have done my time in the seat over the years in lots of different cars - and I sure would admit if I missed a shift big enough to cause what happened to mine. What perplexes me is that I'm seeing such a big multi-pushrod failure after that one drive. The really weird thing is that I wasn't driving the car anywhere near as hard as I've driven it in the past - that was really a test drive to see if my new power steering pump was working right. I was in the middle of a really clean 1-2 shift and going toward redline again in second when it gave up on me. When I first heard the clacking noise, my first thought was that the serpentine belt that I installed was bad and was starting to fray and smack up against something.

To fix it, I'm thinking that I should go with better rockers, heavier springs, and lighter valves, but I'm not so sure about going with stronger pushrods. I like to think that, if something is going to break, the pushrods are a convenient weak link. While the heads are off, I figure I may as well also go with a set of headers. I was really trying to keep this car stock, but I can always keep the original pieces in with the shipping container full of other OEM parts from other cars that I haven't been able to part with...

 

[carguy07]

If you don’t pull the heads I would at least try to get a scope in the cylinders and see if you had some pistons and valves hit. Just worried that you may have now bent some valves.

It’s a long shot, but could you have jumped a tooth on the timing chain? Never heard of it on one of these engines, but other cars with high mileage it can happen.

 

[Jack B]

Stronger pushrods are not necessarily the answer. The T&D or Jessel rockers are a big improvement. When you get ready for a major upgrade, you can do the heads and at that time change the springs, retainers and locks. If you bent a valve, the car would be popping back, The borescope is a good idea.

 

[Martin]

Stronger pushrods are not necessarily the answer. The T&D or Jessel rockers are a big improvement. When you get ready for a major upgrade, you can do the heads and at that time change the springs, retainers and locks. If you bent a valve, the car would be popping back, The borescope is a good idea.

Good point - the car was driving and idling really nice, even with the bent rods. It leads me to think that maybe the valves didn't contact the pistons and the rods just gave up on their own - does that sound reasonable? It sounds strange to me, but I suppose stranger things have happened. I'm going to pull the heads myself and see what is going on in there. The plan is to upgrade the entire valvetrain so that this doesn't happen again.

On that note, after Crazyspeed's comment at the beginning of this thread, I'm thinking strongly about installing some of the Striker heads. I figure if I've gone through the trouble to tear everything all apart, I may as well put it back together better than it was. Also, I don't want to spend $1500+ on rockers for the stock heads that won't be any good on the nice set of heads that I really want to get eventually. In other words, I'm trying to rationalize spending $6K+ on a new set of heads that I probably don't need...

To help me rationalize it, I figure I'll still have the original heads in storage (hopefully in near perfect shape) and I can rebuild them if needed and swap them back in later on in life when the car is about to go on Barret Jackson (again, irrational rationalization).

 

[jay01m]

I wouldn't worry much about OEM internal engine parts. The oldie cars almost all have rebuilt motors, and it doesn't depreciate the value. I say rebuild your stock heads with good parts and be happy. Just my $.02.

 

[GR8_ASP]

I wouldn't worry much about OEM internal engine parts. The oldie cars almost all have rebuilt motors, and it doesn't depreciate the value. I say rebuild your stock heads with good parts and be happy. Just my $.02.

Not to disagree but I doubt that almost old cars have rebuilt motors. Not even close.