PDA

View Full Version : 99 A4 1.8t broken timing belt. Help!!



apenkauski
11-13-2012, 05:58 PM
Hello all, I've been lurking around for awhile now lookin for upgrades and tweeks but now I'm in need of some real help.


About two or three months ago the timing belt on my A4 crapped out.[headbang]

Pulled it apart and this is what I found...

http://www.audizine.com/gallery/data/500/IMAG0220_800x478_.jpg

and

http://www.audizine.com/gallery/data/500/IMAG0215_800x478_.jpg

Do I need to replace the pistons? I know the valves are shot.
Any advice would be appreciated.

Thanks

walky_talky20
11-13-2012, 06:02 PM
Pistons are fine. It would not be a bad idea to smooth out the gashes a bit. The sharp edges can promote engine knock (detonation).

Artiemas
11-13-2012, 06:22 PM
Looks like the valves just knocked the carbon off and cut a little bit of the top of the piston. Like Walky said, smooth them out, as they might nick the side walls, too.

apenkauski
11-14-2012, 06:47 AM
Thanks. I wanted to make sure about the pistons, I figured I could just smooth them out and they'd be ok. I know the head needs to be rebuilt, but could I do this myself as I like to be pretty hands on when it comes to repairs. Also money is tight, so I would like to know what needs to be replaced to get it back on the road. I am currently driving a 1978 Fullsize K5 Blazer that only gets about 4mpg at the moment, so the sooner the better.

I was looking at a Broken Timing Belt kit from Hansautoparts.com that should work, but is there anything else I should replace that isn't included?
Here's the Kit http://www.hansautoparts.com/product-detail.aspx?18TBrokenTimingBeltKit.htm

Again Thanks in advance

walky_talky20
11-14-2012, 07:01 AM
That kit seems to include a lot of extraneous stuff. If money is tight, just buy what you need. My father has fixed several 1.8T's with broken t-belts. He never bought any manifold gaskets, oil pan gaskets, valve seals, or head bolts. Should that stuff officially be replaced? Probably. Will it be fine? Yeah. He generally just buys the valves he needs and puts it back together with a new headgasket. He's had good success with the ebay kits for all 20 valves.

Scotty@Advanced
11-14-2012, 07:19 AM
Pistons are fine. It would not be a bad idea to smooth out the gashes a bit. The sharp edges can promote engine knock (detonation).

I'd check the pistons at least, the top ring land can get crushed and pinch the ring which then results in lower compression. Also there is a substantial nick in the top of the cylinder in the middle in the lower right hand sector of the bore might want to see if that will interfere with the headgasket etc. Also the middle intake valve generally digs into the head and depending upon the depth of the damage, you may need a new head, or at least a repair.

apenkauski
11-16-2012, 10:03 PM
Whats the best way to clean the top of the pistons, a wire wheel maybe? Can I just use a degreaser for the cylinder head? Also should I replace the valve guides as well, if so any cheap places to purchase them?

Sorry for all the questions and thanks in advance.

apenkauski
11-16-2012, 10:08 PM
That kit seems to include a lot of extraneous stuff. If money is tight, just buy what you need. My father has fixed several 1.8T's with broken t-belts. He never bought any manifold gaskets, oil pan gaskets, valve seals, or head bolts. Should that stuff officially be replaced? Probably. Will it be fine? Yeah. He generally just buys the valves he needs and puts it back together with a new headgasket. He's had good success with the ebay kits for all 20 valves.

I know that kit has alot of extra stuff, but I figure the engine has 170,000+ miles so it couldn't hurt to spruce up the seals a bit.

Thanks for the responses.

apenkauski
11-21-2012, 04:20 PM
Whats the best way to clean the top of the pistons, a wire wheel maybe? Can I just use a degreaser for the cylinder head? Also should I replace the valve guides as well, if so any cheap places to purchase them?

Sorry for all the questions and thanks in advance.

Anyone?

nautaqA4
11-21-2012, 05:08 PM
i fully agree with walky i bought my a4 with busted timing belt just cleaned up pistons a bit got ebay valve kit an HG an called it good. oh wait i also did the timing belt tensioner upgrade the pesky ball n cup set up is sketchy at best...

demonmk2
11-21-2012, 06:20 PM
if you can do the rods too (forged) just in case

Jtroiano
11-22-2012, 05:18 PM
I aggree about checking the pistons. Put some new rods, bearings and rings. Also head lots should be replaced everytime. Also I e heard that the block. An get damaged where the valves hit.

That's what mine looked like. Broke a 70mph. Have a customers TT that broke backing out of the driveway. Almost no damage to the pistons.

I cleaned my head and use to to show customers what happens when the belt brakes. Makes it for an easy sell.

Jon