What are the weak spots for higher mileage G8s? - Pontiac G8 Forum: G8 Forums - G8Board.com
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post #1 of 22 (permalink) Old 07-10-2018, 07:32 PM Thread Starter
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What are the weak spots for higher mileage G8s?

My '09 G8 GT has 80,000 miles and has been trouble-free. It's had a fairly easy life and is unmodified. Other than normal maintenance, tires, etc., the only parts I've had to change are the struts, strut mounts/bearings, and rear shocks.

Now that there are a lot of higher mileage G8s out there, I'd like to know if there are known weak points to be aware of based on owner experiences. I don't want to get stranded. Where might I be on "borrowed time?" I am thinking about preventatively replacing the coils and plugs, for example. What about the water pump? Radiator? U joints/CV joints? Certain sensors? Motor mounts? What life are people getting out of their transmissions? Thanks.
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post #2 of 22 (permalink) Old 07-10-2018, 08:43 PM
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Pretty hard to predict what "might" go wrong with the car. Radiators are plastic/aluminum construction and have been known to fail. Some people are near 200k miles on their stock transmissions. Plugs at 100k and I wouldn't bother with coils. I am of the opinion that you shouldn't lose sleep about what might fail. Because you might be lucky and things could go well for another 80k miles for you.

Just fix things as they need. If you are looking to do maintenance, do the regular stuff. Oil change, trans fluid/filter change, rear diff fluid change, plugs at 100k miles, new serpentine belt. Maybe bleed the brakes with fresh fluid. You know, all the regular maintenance stuff.
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post #3 of 22 (permalink) Old 07-10-2018, 09:14 PM
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Your going to drive yourself nuts worrying about what might go wrong.
Drive the car, when it breaks deal with it.
buzzard302 nailed it, move up the frequency of oil changes and do preventative maintenance for the other fluids as you see fit.
Within a couple of weeks of getting my G8 I had replaced all the fluids including coolant and plugs.
I was lucky as my son worked at a local GM dealer so he could take my car and when it wasn't busy put it on the hoist.
Got his discounts too....I cried the day he quit that job....
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post #4 of 22 (permalink) Old 07-11-2018, 11:04 AM
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agreed that all you need to do is the normal pm stuff. be careful driving on cruddy roads and otherwise, when things break. they break. i guess the biggest concerns are paint, lca's, lifters, some belts and pulleys off the top of my head. generally the g8 is pretty well built.
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post #5 of 22 (permalink) Old 07-11-2018, 02:10 PM
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80k is not all that high, pretty normal for these being 10 years old.

Like others have mentioned just keeping up on regular maintenance, the biggest known issue is the lifter failure. A dod delete system will fix this and free up some horsepower as well!
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post #6 of 22 (permalink) Old 07-12-2018, 02:40 PM
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I had 130k on mine when i sold it, 40k of that with 620whp. Only items i had to replace were the alternator, control arms, and struts.
My range rover on the other hand keeps eating parts...

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post #7 of 22 (permalink) Old 07-13-2018, 01:37 AM
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Going to jinx myself but...A/C compressor, fuel pump, bank 2 knock sensor, and something in the underhood junction box that knocked out the fans (probably why A/C compressor went but who knows, also ABS and ESC quit about the same time as said junction box problem) were the only "surprises" so far that I can think of...sitting at a little over 282K as I type. Stock DOD lifters, stock fluids in all but the oil and gas tank...Roll in the 65+ mile trip to work at around 80-85 with the occasional trip to triples to pass slower moving traffic and back home around 65-70 daily (that reminds me, I played with an 8sp auto white StingRay Saturday night on the way home...guess he didn't like getting passed by an older vehicle and tried to speed up and prevent me from getting back over in front of his newer ride so we took a trip up to triple digits, with him close behind, and I let him hear the Max Flows as I downshifted and slooowly came down from triples to make the turn as we came up to the light...LOL). Also still puts a smile on my face 10 years later in the twisties every morning.

Oh and finally threw an A/C belt yesterday morning on the way in to work but that was replaced last year with the compressor...

Just drive the DAMN car she'll love you for it!
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post #8 of 22 (permalink) Old 07-14-2018, 12:17 AM
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As allot have said already, plus front suspension problems are a concern. Check these well. I have replaced almost all the suspension parts. They go dangerously bad quip with the stock parts. The Ball joints are real cheap parts. Any moisture in the sealed boots will cause severe corrosion. They were replaced twice under warranty. Then shortly after. I ended up buying Australian race parts, never a problem again. 100K and going on my G8. The inherent tap from the DOD lifters.
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post #9 of 22 (permalink) Old 07-14-2018, 01:32 PM Thread Starter
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Thanks all, appreciate the comments. Struts/mounts/shocks were done (went with PPV parts and poly mounts). I regularly check the (original) LCAs, and they remain in good shape. Potential lifter failure is news to me... I use AC Delco filters, but will reduce my oil change interval and keep an ear out for unusual ticking. Glad to hear that overall these are quite reliable.
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post #10 of 22 (permalink) Old 07-15-2018, 01:06 AM
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I have used synthetic oil since the first 200 miles of my G8. I have used AC Delco filters also. Still get the DOD lifter tap in the cooler weather. I also get some piston slap. Since new. Had under warranty the lifters replaced. Still taps in cool weather. The noise happens no matter what oil and filter. When they collapse no one knows. Just replace them at high cost and move on. FYI. You just keep up on the recommended maintenance and drive it and enjoy.
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post #11 of 22 (permalink) Old 07-16-2018, 09:44 AM
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Quote:
Originally Posted by LVG8GT View Post
Thanks all, appreciate the comments. Struts/mounts/shocks were done (went with PPV parts and poly mounts). I regularly check the (original) LCAs, and they remain in good shape. Potential lifter failure is news to me... I use AC Delco filters, but will reduce my oil change interval and keep an ear out for unusual ticking. Glad to hear that overall these are quite reliable.
I don't know if you necessarily have to do more oil changes, just check the levels. My stock dod cam will eat almost a quart every summer.
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post #12 of 22 (permalink) Old 07-16-2018, 03:32 PM
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Are you the original owner of the vehicle? Despite some manufacturers touting the perceived benefits of yearly oil changes, recommended regular oil change intervals of 5,000 miles for simplicity's sake. Mind you, this is for conventional oil and would extend the time-frame a wee bit further for synthetic oil. Following the scheduled maintenance service intervals outlined in the owner's manual goes a long way. Would drain and refill any fluid(s) not mentioned in the maintenance schedule every 50,000 miles. Always use distilled versus tap water when mixing with anti-freeze. A visual inspection of suspension and steering components is good and popping the hood at least once a month just to take gander and see if anything is obviously amiss. Am not one to consistently "throw" parts at a vehicle unless it's a last ditch effort to solve the an occurring present failure versus a perceived potential problem. Agreed. Just fix issues as they arise and try not to be overly concerned with what might happen primarily since the possibilities are endless. Happy motoring.

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post #13 of 22 (permalink) Old 07-16-2018, 04:41 PM
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Welp...I did indeed jinx myself. Center driveshaft bearing went out again last night. Limped it back home and will order another one soon and maybe some diff bushings...
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post #14 of 22 (permalink) Old 07-16-2018, 05:59 PM
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Welp...I did indeed jinx myself. Center driveshaft bearing went out again last night. Limped it back home and will order another one soon and maybe some diff bushings...
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post #15 of 22 (permalink) Old 07-20-2018, 11:08 AM
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post #16 of 22 (permalink) Old 07-20-2018, 11:14 AM
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I definitely recommend replacing the radiator. Mine broke a day after I bought it with 136k on her. The hot coolant got all over the paint and luckily I was able to get it off without issue but that could have destroyed the exterior. I pulled over immediately and the motor seems fine.


EDIT: and be sure to get a fully aluminum radiator to replace it, no plastic.. that's why mine failed.


Additionally, you might want to lubricate the hood latch... mine seized after the radiator issue. Lubricate the latch and the hood cable
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post #17 of 22 (permalink) Old 07-20-2018, 06:12 PM
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I have 130,000 on the clock. Is a daily driver. The biggest complaint is the paint chips easy, front wheel bearings (replaced both with Timken units), center driveshaft bearing broke the rubber mount (bearing replaced), roof liner is debonding on few spots, hood prop struts are getting weaker, doors rattle a bit (fixed with black insulation tape). Other than those items is a pretty solid car.

They suffer of LCA (Lower Control Arm) union failure on salted roads. Since I do not drive the car when snows I never have the issue. However, I have a brand new set ready to go when it happens.

I say to stack up on some parts before they fail, that way, you do not have to break the bank trying to fix. Going to buy another mid driveshaft bearing to keep it handy and 2 front ones, seems to fail at about 60,000 or so miles, mine did at about 90,000ish.
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post #18 of 22 (permalink) Old 07-22-2018, 10:30 PM
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I have 130,000 on the clock. Is a daily driver. The biggest complaint is the paint chips easy, front wheel bearings (replaced both with Timken units), center driveshaft bearing broke the rubber mount (bearing replaced), roof liner is debonding on few spots, hood prop struts are getting weaker, doors rattle a bit (fixed with black insulation tape). Other than those items is a pretty solid car.

They suffer of LCA (Lower Control Arm) union failure on salted roads. Since I do not drive the car when snows I never have the issue. However, I have a brand new set ready to go when it happens.

I say to stack up on some parts before they fail, that way, you do not have to break the bank trying to fix. Going to buy another mid driveshaft bearing to keep it handy and 2 front ones, seems to fail at about 60,000 or so miles, mine did at about 90,000ish.
My center bearing lasted till a tick over 240K but the new one less than 40K...what gives???

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post #19 of 22 (permalink) Old 07-23-2018, 05:45 AM
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Forgot to mention, the center bearing rubber mounts gave at about 125,000 miles.

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post #20 of 22 (permalink) Old 07-23-2018, 03:56 PM
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Ok...just got back from putting it up on the lift to inspect it...the cage with the bearing and rubber broke from the mounting. So now either order a new one or have a one piece driveshaft made..LOL !!!
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