Hyundai Timing Belt: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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Dec. 12, 2011 10:52 p.m. CarKid1989 Dork

A friend of mine has a 2002 Hyundai Sonata (2.7L) with about 150K miles. Buying a new car is not an option at the moment, she wants it to last another year.Timing belt snapped on her way home on the free way and seeing as how these are interference engines i assume damage was done.

So, she called me up to fix it or think about fixing it for her.

A) Do i retime the engine throw a belt on it, cross my fingers and see if it will run? If not no harm it was alreadyt broken

B) Can i figure out if it just needs two new cylinder heads somehow? Camera in the spark plug holes? If no piston damage was done ill just toss on heads and call it a day.

C) Accept the fact that engine is prob toast and throw in a used motor (apx 500$) and call it a day.

I dunno if im taking on the job yet, dunno if i have the time for another engine replacement at the moment.

Thoughts?
Dec. 13, 2011 6:47 a.m. DrBoost SuperDork

Pull the cam cover off and rotate the camshaft by hand. watch to see if any of the valves to not return to the closed position. If you see a gap between the tapped and the cam, assume a bent valve stem at the least. At that point, the head comes off and the money starts rolling out.
The only time I've ever known an interference engine break a timing belt with no damage was because the engine was idling in my stall when it broke.
Dec. 13, 2011 7:03 a.m. Streetwiseguy Dork

As far as diagnosis goes, do whatever is easiest. If you can toss a belt at it and fire it up easier than removing valve covers and checking clearances, which is easier than rotating cams and crank to perform a leakdown test...In your situation, I will usually retime and put a belt on first. Its pretty easy to do a compression test afterwards, but you'll probably hear the dead miss as soon as it starts.
Dec. 13, 2011 7:34 a.m. Bobzilla SuperDork

putting on the t-belt in the 2.7 sucks bal..... it's not fun. Pull the cam covers and check the clearances. If it was running when it snapped, it's likely toast.
Dec. 13, 2011 7:53 a.m. mad_machine SuperDork

you should still be able to do a static compression test with a compressor and a gage.

Just make sure the cylinder you are working on has the valves close and go to town. Any leakage will be quite evident
Dec. 13, 2011 9:50 a.m. belteshazzar SuperDork

i found that to be one of the easier V6 timing belts to do. Good accessibility and a straightforward design.

throw a belt on and see what you've got.