I had timing chain go bad on the engine and bent valves. Replaced valves replaced vvt gears replaced chain. Had the head inspected and pressure tested. When i dont put on the timing chain and do leak down test every cyclinder checks in the green on the leak down gauge. When I place the chain on algining to timing marks try to start engine I have very low compression. What am I missing?
Waiting for a mechanic. I’ve only done one and never had that kind of substantial damage. But possible one of the sprockets sheared and shifted, timing marks not correctly chosen, etc. look for more damage.
Crazy thing is when first happened I put it back together car ran however gave me alarm that stated vvt gear because first time putting back together I used old vvt gears. After replacing them has not ran. I had ordered from Amazon so figured they may have been China crap so then bought OEM and did find differences however same result
Your timing mark lines up at a few degrees before top dead center and bottom dead center. are you sure your number one piston was at the top before setting the ignition timing?
Yes very sure
You might try posting pictures so maybe someone will see something that could be wrong…
Did you assemble the head or did the machine shop??
Have you tried manually rotating the engine (using a ratchet/socket on the crank bolt) with the valve cover(s) removed? Do the valves seem to move into the correct position w/respect to the pistons? i.e. at the top of the compression stroke both intake and exhaust valves for that piston should be in the closed (unpushed) state. If overhead cam, the respective cam lobes should be pointing up, away from the valve.
If you haven’t yet done that experiment, suggest the first step is to remove valve cover(s), and spark plugs and see what is happening w/the valves as you manually rotate the engine. If the valves are in the correct position, about the only thing left is the piston rings aren’t sealing correctly.
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I have made sure I had top dead center on piston one the intake lobe is straight up the exhaust lobe is in the 7 o’clock position. Is that correct?
As long as both intake & exhaust valves are closed, seems more or less correct. The cam should be configured at TDC-compression such that the exhaust valve is next to to open, towards the end of the power stroke. I’m a little confused that the exhaust lobe is oriented at 7 pm. Maybe it is really at 4-5 pm, on the way toward 6 pm when it opens the exhaust valve?
Does this orientation apply to one of the cylinders that measures questionable compression?
It is at 7 and as I rotate the crank it is heading to 8 position
That seems incorrect to be. If it is heading towards 8 pm, the exhaust valve isn’t going to be opening for quite some time. It seems like the exhaust valve should be opening pretty soon, at the end of the power stroke. TDC-compression is at the beginning of the power stroke, right? Maybe somebody more knowledgeable about the basics of camshaft timing will chime in and clarify the situation. Cross your fingers, perhaps you’ve discovered the compression problem.
Are you sure you are manually turning the crankshaft in the correct direction? On both of my cars IIRC the crankshaft turns clockwise as I look at the crank pulley.
Thank you yes hopefully someone can chime in. Need to get this car done for my daughter
Sometimes diy’ers get confused by the timing marks. Some of the marks are used by the manufacturing staff who build the engines at the plant using a special purpose build-fixture, not intended for use by diy’ers installing timing belts/chains in their driveway.
Again, try posting some pictures of ALL the timing marks and how you have them all set…
I guess this is for your vehicle, it is supposed to be from ALLData…
Since I am new I am only allowed one picture and yes that us how I set it. That is why I am frustrated.
You should be able to post a picture per replay at least…
I see a colored link between the links…
That was pic after I had rotated it couple times to make sure I did not have valve interference
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I did set it to the 10 and 2 position.