|Topic Review (Newest First)|
|08-09-2019 03:47 PM|
|marksbug||cloyes has a good utube vid and great timing kits too, not the cheep china stuff. your more than likely gonna need a set of valves too.possiably a valve job...possiably a new head quite a few posibilitys. but just timing chain aint gonna fix it. you could pull the valve cover and see if there is loose rockers on those cylinders when the lobe is off the rocker arm, check them all, if they are loose then yup those valves are bent.hopefuly the guides did not get cracked or seats get whaumped.|
|08-09-2019 08:23 AM|
Originally Posted by yevgenievich View Post
|08-08-2019 11:52 PM|
Originally Posted by raygun View Post
|08-08-2019 11:07 PM|
Well, sure, if you want to do it the easy, direct and most efficient way.
But, getting the intake manifold took just a bit longer than 10 minutes for me the first time. Itíll have to come off in any case to remove the head, so may as well start there and inspect the valves.
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|08-08-2019 10:58 PM|
|Saveaux||Remove your intake and look at your valves, it only takes 10 min. As Raygun stated, the ATK engine is easy enough to swap out, I just did it. I burned a hole through piston number two, and had zero compression at 37k miles, I think youre more likely to have bent valves.|
|08-08-2019 03:02 PM|
|yevgenievich||Pistons can be not happy, but can be put back to work in a pinch. Not recommended on a forced induction motor.|
|08-08-2019 12:39 PM|
No compression can be caused by a few things:
- Bad rings. Unlikely in your situation, and you'd typically see low compression, not zero. And, having rings on two cylinders suddenly die would be pretty surprising.
- Head gasket. Same as above. Also, you typically see low compression on adjacent cylinders, not on two that are not adjacent.
- Valves not closing, possibly due to broken valves, broken valve springs, bad guides, etc. It'd probably be smarter to replace the head then to try and rebuild it in that case. But, having broken components on just two cylinders is unlikely (but certainly not impossible).
- Cams (and therefore valves) are out of sync with the crank due to the timing chain jumping. This is pretty hard to do without, at minimum, trashing the valves. The reason you'd see low compression on cylinders 1 and 3 but not 2 and 4 (or vice versa) is that, if the cam is, say, 90į out of phase, then the valves would be open while the piston is on its compression stroke. The even cylinders are 180į out of phase with the odd cylinders.
In order for that to happen, the timing chain would have to jump - a LOT - or the cam gear would have to come loose, allowing it to rotate without moving the cam sufficiently. If your timing chain is loose enough - I'm guessing due to a bad guide or tensioner - this could happen, but may end with the pistons slapping the valves. That would certainly destroy the valves and probably won't make the pistons happy, either.
In any case, the head is going to have to come off. Just installing a new timing set will not correct the problem.
A replacement LNF will run you about $2400. ATK is a very reliable supplier. Installation isn't difficult if you have the space and tools, but it does take some effort. (Duh.)
|08-07-2019 08:46 AM|
Originally Posted by JohnWR View Post
|08-07-2019 05:54 AM|
|JohnWR||Go to helminc.com and buy the factory service manual. The last time I looked the set was $300.|
|08-06-2019 10:08 PM|
I've been told that I'm very likely looking at bent valves and minimum head removal to fix. I'll turn the crank to see of the chain gets tight - I suspect it will.
What's the best source for a manual for this car to know best way to go about this??
Also, having not done one of these engines before, what do I need to be concerned about and what if any special tools are needed?
Thanks in advance,
|08-06-2019 09:06 PM|
|SSolstice||Before you replace the timing chain, rotate the engine (clock wise) to see if the timing chain tightens|
|08-06-2019 06:27 PM|
|The_Ghost||This is a zero tolerance motor, so if the timing chain is that bad, you might have crushed the valves.|
|08-06-2019 04:38 PM|
|JohnWR||Instead of a compression test you might want to try a leak-down test so that you can tell how the air is escaping.|
|08-06-2019 04:22 PM|
If you have no compression on two cylinders it sounds serious. our engines are interference engines and if the timing gears have slipped out of time or the chain has broken, you could have destroyed valves, pistons or both. If you are getting even low compression on all four, it may not be so bad.
There is a video on youtube. i think it is titled ECOTECH TIMING CHAIN REPLACEMENT that will give you a pretty good idea of what is involved.
check that compression again and good luck.
|08-06-2019 02:10 PM|
|LatinVenom||If you really do not have a any compression on cylinders 2 and 4 then is an engine rebuild or another engine new or use.|
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