Timing jumped. Bent valves. New head or rebuild this head?

[fourgsixthree33]

So after a 150 mile trip to my dads for a family get together, I think the timing belt jumped and I bent valves. Going up a steep hill on my dads road, I head a pinging/knocking noise and threw out some grayish smoke. Not long after there was a pop and the noise got louder.

Tore the car apart, found that my timing jumped. Retimed the engine and still has the noise. The car sounds normal, just has a pinging noise coming from the head. Please note I stopped when this happened but have idled it after redoing the timing belt.

I think it is only one valve. I haven't taken the head off yet. My question is should I buy a new complete head or have this one decked with new valves?

I would like to take my time and get some larger valves and cams. Them a cometic head gasket and arp head studs. I would hate to do all this work to keep it in stock form.

How much would I be looking at to get the head decked? Would it be worth it to fix this head?

Engine is in a 93 tsi awd auto 7 bolt.

 

[superorange]

i am in the same boat and got a quote from a local place $250

i would say it is worth it that way you know the head is fresh, thats the route im going to go. i have heard of ppl buying new heads and then finding out it wasn't the greatest.

 

[fourgsixthree33]

Like I said, I might as well take my time. If I build my own head after this one is decked, etc, and get some cams and larger valves, I think I would like that alot.

If any of my valves are bent, would the car still sound normal? Like I stated above, the car sounds normal at idle and even after reving it to 1500RPMs. I am pretty sure the noise is coming from the head.

I pulled the VC and all the rockers are good. Haven't done a compression test. I am back home now with a loaner car.

 

[beihl304]

Same happened to me not too long ago however I bent all the intake valves besides the 2 in the number 1 cylinder. My car no longer ran after that obviously. If one of your valves are bent, I would think you would notice a poor running engine due to the compression loss in the cylinder with the bent valve.

I decided to just buy a known used good head and swapped the heads since it is infact cheaper to due that then buy valves alone. If you have the money then I suggest doing it right, basically rebuilding it and decking it.

 

[5150DSM]

You might want to check the bottom end. You "think" the noise is coming from the head but I would make sure. Additionally, you said your rockers are fine. I take this to mean that they weren't laying in the VC when you checked things out? If this is the case, it is unlikely that you bent valves, especially if the car starts and runs normally.
At the very least, drain your oil and look for that tell-tale metallic shine and/or metal shavings, chunks, etc... In my experience, knocking sounds are generally associated with rotating and/or reciprocating parts. My 2 cents.

 

[fourgsixthree33]

Thanks for the replies. When this all happend, it ran normal when it started knocking or pinging. Up a large hill and I was going probably 55mph. Which was over the speed limit on a rural road. But she came up the hill strong. Looked in the mirror and she was throwing out alot of smoke. Then a couple miles later, there was a pop and a puff of smoke from the hood. I immediatlely pulled over and had it towed to my dads.

I just dont want to go buy a new head if I dont need to. I dont think the turbo is messed up or anything either. The noise seemed to be coming from the head.

 

[Bud92gsx]

What abooot your parts car..Can't you just rip The head off the other car and go fro there..Thats where I would start..Then you can build the head thats broken, and swap that on when it's time..If It jumped timing then yes bent valve is probably the case..

 

[fourgsixthree33]

The parts car was a NA. I have a good NA head sitting but not a 4g63T head.

I was going to do a compression test before taking the belt off. Should have done it when I redid the belt. But then I took the belt back off. By then I ran out of time. Had to work the next morning and had a 150 mile trip.

Again, when I let the car idle, it sounded normal. It just knocks/pings. If a valve was bent, just one and not several, would the engine still sound up to par? Or would it sound like crap?

This is the same head that withstood a snapped timing belt at 55mph. Somehow, my gf got away with only having to replace the belt. She never had to replace the head or any valves. I have a feeling the valves weren't perfect by the time I got the car.

Another thing that is weird is the knocking noise happend all of a sudden, with no difference in performance. The entire day of driving the day this happend, it wasn't nearly as powerful as it usually was, but the noise didnt occur until I was near my fathers, 150 miles from home.

Then a few miles later was the pop and puff of smoke from the hood. Car was still under power. I immediately stopped on the side of the road. Dad pulled me home and I let the car idle for the remainder of the 5 miles to his house since I have an AWD. Figured fluid would still pump through the drivetrain.

I have revved the engine to 1500RPMs and it sounds normal. The pop and puff of smoke was not a first to me as this is the exact same thing that happend when blowing two timing belts on 2 previous DSM's. So I am sure you know what I mean when trying to describe that. We have almost all know what that is like.

 

[Bud92gsx]

What you need to do is a compression test, and a leakdown test..That will tell if if one of you valves are bent, It will be leaking air, you will be able to hear it...

Iv'e had that boob and smoke before but, it turned out to be nothing..I think it was just carbon build up and it finally gave way..But it could have also been a problem with the head..Maybe I need to do these tests too..

 

[diamondstargsx]

pull the head and take it to the machine shop,have them check it and call it a day!
its the only choice you have so get to work!

 

[fourgsixthree33]

This does sound like a bent valve issue though right? I just dont want to spend money on a head and it turn out to be something in the lower end. I have some plans for a head I want to build.

When I am able to go back up to my fathers, I will pull the head. Right now I just wanted to explain what happend and see if you guys think it is a bent valve.

 

[92AWDHX40]

Ive used my nt head on my turbo not sure whats on now.

 

[fourgsixthree33]

You swapped the cams right? What about the valves? Found a guy with an evo 3 head that I will most likely buy in a couple of weeks.

If I decide to get aftermarket cams and valves, what would be some good choices that aren't too costly? I would like to buy used cams.