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Hello from Las Vegas.


I wanted to offer up some advice to Equinox and Terrain owners with the 2.4 engine. I have an ad on Craigslist that offers my services on Ecotec engines. I offer tune-ups, SMOG repair, timing chain replacement, and full engine rebuilds. I work out of my garage as a hobby and second income. Last week I had two vehicles dropped off to me from other shops here in Vegas that could not get them running again. Both stories were identical. Vehicles towed in with a no start complaint. Diagnosis was that engine timing system failed and jumped causing bent valves. Cylinder heads were removed and sent out to 2 different machine shops for reconditioning. Upon re-installation of head and new timing sets the engines still had no compression. Timing sets were removed and re-installed to no change in result. Shops informed owners that possibly block was cracked or piston rings broke and engine would need to come out. I was contacted by one owner and by one shop manager to inquire about a rebuild. I asked for vehicles to be towed to me for an estimate. I also asked for all broken/damaged parts from each repair to be sent along. Both engines had broken front timing guides (cam to crank timing chain). Each guide snapped into 2 pieces “jamming” the chain in a way that skipped timing. However prior to altering timing it spun the snout on the intake camshaft by several degrees. Machine shops assume cams are good if all the lobes are free of scoring and the snout is free of damage. They re-install and call it done. This is why GM dealerships replace cylinder heads as opposed to repairing (in my opinion). Unless you have a known good cam to compare to, you simply cannot know that the pressed on snout has moved or is still aligned. Luckily, in both cases the snout had moved in a way that simply caused intake and exhaust valves to be open simultaneously without pistons colliding into them, but no compression.


So if your shop is going to rebuild your head to repair, might want to provide them with a new intake camshaft. I have not seen an exhaust camshaft suffer this fate. I was ready for this situation from experiencing it once before. It was **** to figure out. I reset timing chain 3 times (like a fool hoping for different outcome). I blamed the machine shop for possible putting wrong cam back on my head. I finally tried a head from a known good vehicle and had compression. That eliminated the short block as cause. So I started tearing apart the original head to find NOTHING wrong. I assumed the snouts were all part of the machined cam. I didn't know they were pressed on. I ordered new cams and upon installing them I saw clearly the difference in key way locations. 3 weeks of misery and the light bulb went on.


Sorry to ramble, but this can be a big difference in repair. A complete engine vs cylinder head repair.


Replace your timing chain before it fails!! IT WILL FAIL.
 

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Just out of interest, what is the usual milage failure of chains and what do you charge to replace (I know it varies a lot depending on area) the timing chain.
 

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Just out of interest, what is the usual milage failure of chains and what do you charge to replace (I know it varies a lot depending on area) the timing chain.
I’ve driven the last three vehicles I’ve bought new well over 222,222 miles and never changed the timing chains on any of them. So my experience says “they last forever - as long as they aren’t starved of lubrication” - which is what ends up happening with some of those 2.4L Equinox/Terrain engines.

As far as replacement cost, I think I’ve seen Independent quotes of around $1200-$1500. We’ve been through this estimate before ... to me - if you call yourself a “professional mechanic”, and you therefore have a hydraulic lift and all your tools right there “at the ready”, AND you’ve presumably done at least one of these jobs previously (so you have some experience, which greatly speeds things up) ... you should be able to replace a timing chain on one of these engines in an 8-hour workday. And if your Independent rate is $100/hour, and the parts are $400, that’s $1200.

Dealership rate would probably be more like $130/hour, I’m guessing ... and they’d kill you more on the parts, too..,

Someone will chime in with the “Book Number” for this job. Can’t remember what it was quoted at previously ...
 
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