no compression in cylinder 2 (bad valve) help!!!

[streetxtreme]

i was driving on the highway, and when i mean drving, i was just crusing at 2500-3000 rpm in 5th gear
i was playing with my safc previous of getting on the highway to try to lean it out a little bit for better gas milage
my settings were
1000 +2
2000 0
3000 -5
4000 -5
5000 -5
6000 -5
7000 -5

the LTFT was 0% steady but the STFT was jumping around between 0 and 10

to me that means that i have it tuned pretty well

THEN suddenly my car starts to misfire after on the highway for 5 minutes
the car started to vibrate a little during acceleration
then get worse and worse

i took it home and did a compression test
compression was 135, 150, 0 150
i poured some oil in the cylinder with 0 compression and it didn't help
so that made me confirm that it was the valves no sealing

i do not get a tapping sound either
could it be that my valve seat is not sealing?
I DO HAVE OIL BURNING FROM BAD VALVE SEALS
could the oil have corroded up the seat?

ANY help or suggestions would be appreciated!
thanks for reading

 

[tqmx1]

Things like that don't fix themselves. It's time to pull the head and see what is going on inside. That is unless you have Xray vision then you have to take it apart to fix it anyway.

 

[DSM90AWD]

Zero compression in that scenario is likely the result of a bent valve(s). Possible you skipped time on the belt/ threw a cam follower. You can pop the valve cover off and rotate the crank pulley to see if any of the valves are stuck open to check, but in the end you are going to have to remove the head.

That sucks

 

[streetxtreme]

if i skipped a tooth, wouldn't it bend more than one valve
i was thinking about the oil burning problem might off fouled up the seat , and the problem just got worse over time until it finally gave up
i checked the compression last week and it was 130, 150, 150 , 150
this time it is 130 , 150, 0, 150
so if timing was off, i don't think i'll be getting the same compression in the other cylinders

 

[tqmx1]

With that low my guess is you burned a valve or knocked the ring lands out of the piston. If you realy think it's a valve hainging you can spike the valves on that cylinder and see if it comes back. But thats like putting a bandaide on a sucking chest wound.

 

[DSM90AWD]

We can e-speculate all day (headgasket, valve, ring land), but in the end, the head will need to come off to know for sure / repair it.

You do not want to be driving the car with 0 compression

 

[GS-T_Newboost]

0 comperssion means bent valves. tuneing does not make valves stop seating

 

[streetxtreme]

how do you bend a valve when your not even pushing the car?
i was only driving 2000-3000 rpm in 5th gears
then it slowly happened



this vibration problem happened about 1 month ago....but it fixed itself after drving on the highway for 300km

i couldn't stop driving because i was on the highway going from montreal to toronto. and it was super dark and i was in the middle of no where.

 

[TermTrky]

Your compression numbers should be around 170-190, depending on N/T or turbo. I have a bad valve and it's reading 150. Your car is such low mileage, it's a shame. Compression is rings / cylinder wall sealing around piston, valves, and head gasket. In the Hayne's manual, while doing the compression reading, you will see a small jump [0-30% of final reading] first stroke, and then it will make the rest of the way to the final reading [which will be low] if a piston ring is an issue. For a valve or head gasket, it will make 40-75% of the distance to final reading in first couple of strokes, and then span the gap to final reading. Percentages are rough estimates, and only to be taken relatively [as reading compression and deciphering what it means is relative as well]. I made up the percentages to help understand what to look for. Pull your head buddy! My block has 150K and it's beat-up and it reads 175 175 170 155 and that's with a bad head gasket and valve issues. Should read 190 though. :[.

Best of luck to you and all of our DSM voodoo issues!

 

[Defiant]

You've burned an exhaust valve.

 

[Icarus]

Defiant I was gonna say burnt valve too. It's happened to me before. I didn't want to pull the head without confirming it first though. This is what I did to track it down.

1. Pressureized each cylinder. Listened to intake and exhaust for which side. Confirmed exhaust side.

2. Removed exhaust manifold.

3. Visual inspection confirmed all valves were seating properly.

4. Found air leaking from #2 exhaust port and upon closer inspection noticed a crack on the back side of the valve (A cheap dental mirror would be quite handy here).

In the end whole lot easier and cheaper than pulling the head. And if it is burnt then you know what parts to order and the exhaust manifold is off already

 

[streetxtreme]

YOU GUYS ARE RIGHT!

the head is off and 1 exhaust valve is burnt
what could have caused this?

my LTFT were 0 on the dot

and i wasn't even boosting. just crusing at 100km on the highway at 2500-3000 rpm max
the it started to shake and got worse as i drove

i don't want this to happen again since i'm upgrading to stainless valves


WHAT WENT WRONG HERE????

 

[streetxtreme]

what do you guy think of this valve set: eBay Motors: 4G63 stainless valves, stock size H/P Eclipse & Turbo (item 130177551921 end time Dec-01-07 13:02:49 PST)

what about these broze guides?:

eBay Motors: 4G63 bronze guides ECLIPSE & Turbo, Hyundai 2.0L DOHC (item 130177008915 end time Nov-29-07 16:03:43 PST)


they are both from ebay
i bought the 3rd gen lifters from him before and everything is still good.