Another 'help me with my car problems' thread

[Pepsi90919]

92 bonneville, 3.8 V6 fuel injected/non-supercharged 3800, 244,000 km. transmission fluid changed at about 225,000 km.

1) 'thunk' or 'TINK' [i suck at describing noises] noise after either putting transmission into drive or [much less likely] accelerating from a stop or slow speed. DOES NOT HAPPEN ALL THE TIME and is barely noticeable. sometimes it will happen when i am going in reverse out of my driveway, well after i am in gear and the car is rolling, which seems odd. i had cv joints checked out and i was told they were fine.

2) i heard this engine is bulletproof. i currently use synthetic oil and change about 10,000 km's. also use bosch +4's and a k&n. how long can i expect the engine to last under these conditions? i want to prolong it as long as possible.

 

[schdaddy]

burning the vehicle might help.

 

[Heisenberg]

*backward American trying to convert kilometers to miles*

Sounds like the tranny may be starting to give. That's a lot of miles for a tranny. I don't know specifically what's wrong but anytime they start to make noise or shift hard something is not right.

A well-taken-care-of engine can probably make it to 200,000 miles with minor fixes here and there.

 

[etech]

If you are talkingabout K&N air filters...
I have heard that the K&N filters do not filter the smaller particles very well. They get their flow from having large holes. If you want your engine to last as long as possible I'd ditch the K&N.

You might want to poke aroung the Edmunds Town Hall discussion on Pontiac Bonneville Problems for more advice and info.

 

[Brutuskend]

Could be a broken motor mount or trans. mount.

 

[olds]

If it's rear wheel drive, check the u-joints.

 

[Viperoni]

I heard that the Bosch's platinum can sometimes break off and cause major engine 5h!ttery to happen.....from a pretty well respected source too.

Too damm expensive for me anyhow

Does the noise happen RIGHT after you put it in gear, or a few seconds after?

 

[fastz28]

<< If it's rear wheel drive, check the u-joints. >>



Yep, u-joint or the transmission is dying. Pray for u-joint.

 

[StrangeRanger]

If the thunk/tink happens just after putting in gear, or when starting from a stop it sounds like your tranny has got some issues. Automatic trannys with that many miles can start to wear considerably. The thunk/tink is caused by having play between parts that shouldn't have any play.
It's kind of a catch 22 tho. You can spend some $$ now to get the tranny diagnosed. If you catch it early enough it could simply need to be adjusted and have some worn parts replaced. But even just getting it diagnosed can cost a good amount of cash. Or, you can wait till it gets real bad, which will cost even more to fix or even replace. If it must be replaced look for a used or rebuilt tranny for sure. A car with that many miles is not worth a new one.
j

 

I heard that the Bosch's platinum can sometimes break off and cause major engine 5h!ttery to happen

You heard wrong,the only reason Bosch plugs break is from incompetant mechanics.

This Bonneville is front wheel drive.
The most likely cause are weak or broken motor/tranny mounts. and/or dog bones.
The clunking you hear is the engine/tranny moving in it's cradle.

Does the tranny shift fine when cold and hot?

 

[IshmaelLeaver]

3800 V6s tend to last about 250,000 miles.

 

[Pepsi90919]

ok, tons of questions to answer here

1) front wheel drive

2) burning the vehicle might help, but unfortunately i would have to way to get to work so... but then again who needs a job if you have no car to blow it on! hmm...

3) i've heard from both sides on the K&N's, i'm really not sure what to say so i'll just keep my mouth shut there i guess.

4) see #5

5) see #4

6) where are the motor mounts and is there any DIY testing i could do to see if it's really that? like shaking the engine? to recap, it only does it after it's been driven (or warmed up) a while.

7) another noise i forgot to mention that might not be anything at all and it has always done it, is a kind of whoooooOOOOoooommmmm..... that appears around 60km/h at total randomness, usually while colder, not a harsh noise and is not affected by engine speed, tires or brakes.

8) tranny shifts fine in all weather. fluid seems to be good as of late.

9) i only heard one story about the platinums becoming +3's so to speak...and you'd think i might notice that ...seriously though, all this stuff occurred before they were put in.

10) there is no 10

11) the noise happens USUALLY [as in 95% of the time] when you throw it in drive. 0.5% of the time it will be in reverse, 4% when you accel from a stop, and 0.5% of the time it will be about 2-3 seconds after you've been in reverse. these are professional figures that have been professionally prepared by Pepsi90919, inc.


thanks everyone

 

[Pepsi90919]

<< and/or dog bones. >>

???????????

 

[Zenmervolt]

Sounds like an engine or tranny mount. Seems to me that if it were the tranny then you would have problems when it shifts gears. I would think that the tranny has another 80,000 km in it, but that's not always the case. When my tranny went south (at 204,905 miles or 329,762 km) it went very suddenly (big shudder when shifting into 3rd on an onramp, then no 4th at all) with no preliminaries though I may have just been unlucky. Still, according to my mechanic the average automatic tranny is good for 100,000 miles for sure, probably 150,000 miles, and once you get up near 200,000 miles you're taking your chances. Have all the engine and tranny mounts inspected and pray that they are the culpret. The tranny rebuild for my car (1988 Accord) ran me over two thousand.

ZV

EDIT: I believe that the "dog bones" are the tranny's shift forks (also called shift dogs) which can wear significantly over time. I was amazed at how worn the old shift dogs and clutch packs were when I looked at the old parts of my tranny.

 

[Pepsi90919]

thanks

i'll have them inspect it sometime soon. i hate the idea of driving on borrowed time.

when the fluid was changed (it was done because of the stupid worn out TCC solenoid problem, which is still there [i should really get that fixed too]) they did a 'transmission service' and said everything internally and externally looked fine.

weeeeeird.

 

[Pepsi90919]

btw, any estimates on the worst case scenario of the engine and transmission mounts being bad?

$$$