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Knocking Noise/Vibration When Getting Underway


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Hi all -

 

I picked up my 975 dollar 2000 Outback, and as expected it has some issues.

 

Hoping you can help me sort them out.

 

1) My biggest concern is the knocking noise when first getting underway. It seems to come from directly below the driver's seat or slightly more aft. It's a vibration/knock. Viscous coupler? U-joint? How can I tell?

 

2) The axle grease burning smell is pretty bad - I'm assuming I probably have a torn axle boot pouring grease on the exhaust? The smell gets into the cabin and smokes a bit outside too.

 

 

Other than that the car seems pretty good - but the vibration/knocking is a concern...

 

5201725673_6d2fae6ff3_o_d.jpg

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sounds like it could be the drive shaft thumping.

 

is it an auto trans?? if so, installing the FWD fuse may relieve the issue temporarily.

 

you are going to need to crawl under there and have a look. shake and wiggle the drive shat, it may be the carrier support bearing.

 

while you are checking it out, look for seepage at the head gaskets.

 

looks like a nice car.

 

congrats.

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thanks!!

 

Yeah I'm thinking driveshaft too. It's a 5 speed - car has 250K miles on it, but seems to have been well maintained. I checked head gaskets before buying it, and all was well - tried my best to overheat it, smell coolant, find seepage and couldn't find any of the above.

 

 

So would the center diff/VC only thump thump on turns?

 

I'm sure the car has a bad CV by the way, since I have that oh-so-familiar burning axle grease smell

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So would the center diff/VC only thump thump on turns?

 

 

this may be a matter of vocabulary.

 

thumping is not a typical failure symptom of the center diff. however, binding in tight turns is. and different folks use different terms to describe binding.

 

to check for it, drive at idle in slow tight turns, all the way to the tightest turn you can make. if the car is binding it will not want to go with out giving it gas, or if it does it will buck, shutter, jump, or maybe thump. but thump is not a term i would use to describe it.

 

thumping at take off going straight is going to be some thing else. drive shaft probably, maybe.

 

i would install a used shaft , if needed. look here :

 

www.car-part.com and or place a wanted ad in our classifieds.

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Agree with others, it is prolly a half shaft, or maybe both half shafts gone bad. Crawl underneath the engine with a flashlight and look at both the inner and outer boots at each end of a half shaft. My guess is that you will find a torn boot or two that has been that way for quite a while. Replacing the half shaft(s) is an ez do it yourself job, or not costly, about $135 in labor per side if work is done at a garage.

 

I think the 2000 model went to phase 2 engine, so head gasket problem is minimized. On that motor, a bad HG will leak coolant to the outside, but not to the cooling system. So issue is simply running low on coolant if you have HG problems. An additive by Subaru is available for the cooling system to fix this.

 

Good luck with your new car. Looks good in the picture.

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just to clarify: driveshaft - shaft from trans to rear diff. cv shaft - front axle shafts from trans to the knuckles.

 

1. driveshaft ujoints or carrier bearing is hosed or

2. one of your inner CV joints is bad.

 

if you have bad grease smell and it's grease flinging off one of your inner boots then i'd guess it's that axle that's causing the vibration. since the joint is hosed anyway, i'd start by replacing that first before the driveshaft since you know it needs replaced.

 

aftermarkets are terrible for this job, get a used Subaru axle and install it or reboot it first or get one from MWE freshly and properly rebuilt. used subaru axles are only $25-$30 each.

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thanks a lot. Yeah it makes the noise in turns, but does not feel like it's holding back at all - more like thump, release, thump, release.....

Leaking grease - thumping, release. Replace the cv joint. Lets get that out of the equation and look at the transmission mount and the uni joints in the driveshaft. You are at the right mileage for a driveshaft to start getting difficult.

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Well- diagnosis is new driveshaft. I'm having it done tomorrow along with snow tire install and timing belt/timing belt cover seal. The area around the oil pump and timing belt cover is leaking pretty bad, which is my burning smell.

 

So 1500 bucks in work. Not the end of the world I guess for a grand total of 2475 for the car

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Well- diagnosis is new driveshaft. I'm having it done tomorrow along with snow tire install and timing belt/timing belt cover seal. The area around the oil pump and timing belt cover is leaking pretty bad, which is my burning smell.

 

So 1500 bucks in work. Not the end of the world I guess for a grand total of 2475 for the car

 

let me be the first to say that the leak at the oil pump is likely the o-ring behind the oil pump or the screws on the backing plate which may be loose. if resealing the oil pump is not part of the plan i strongly suggest you add it.

 

or it may still leak.

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yep - reseal the front of the engine. if the timing belt is coming off then the couple $4 seals are staring you in the face. no point in not replacing any that aren't bone dry. if they're wet or dirty at all, replace them and reseal the oil pump. $20 in parts to reseal the entire front of the engine and it's all right there with the belt off.

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thanks! How does 1600 sound to do the driveshaft, timing belt, all front engine seals including oil pump, rear diff fluid?

 

Some of these are things I could definitely do myself, but I think I'm in 'I just want it done' mode

 

asking folks who do their own work about a price is likely to be disappointing.

 

look at it from your own perspective, how many miles will you have to drive the car to be satisfied that you made the right decision.? 50k miles for 2500$ would make me happy, of course 100k would make me happier.

 

 

happy motoring, enjoy!!

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good point, thanks!

 

Well, I'm not entirely opposed to doing the timing belt myself - how difficult is it to do along with the oil pump seals? thanks again

 

i did my timing belt and i am not a mechanic. i am however a relatively smart guy with an aptitude for mechanical stuff. the hard part for me is the unknown, stuff i have never done before. when i do something for the first time i never move on to the next step until i completely understand the current step. this makes me very slow on new stuff but it tends to avoid fatal mistakes.

 

the timing belt is very straight forward as long as you know the timing marks you are supposed to use. using the wrong marks is an common mistake for first timers.

 

the oil pump re-seal is not hard. it is a $3 o-ring from the dealer and a check, possible ''threadlock'', on some screws, and a tube of ultra-gray sealant.

 

all the info you need is right here on this site you just have to search and or ask.

 

reguarding the drive shaft, i hope you are planing on using a used drive shaft. they rarely fail and the new ones are off the charts. drive shafts are really easy to replace. more so than timing belts.

 

look for parts here:

 

http://www.car-part.com

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Well- diagnosis is new driveshaft. I'm having it done tomorrow along with snow tire install and timing belt/timing belt cover seal. The area around the oil pump and timing belt cover is leaking pretty bad, which is my burning smell.

 

So 1500 bucks in work. Not the end of the world I guess for a grand total of 2475 for the car

 

 

On a older used car my rule of thumb is in the first year expect to put at least 50% of the purchase price back into it, so thats about right. Where is the driveshaft coming from?

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Eh I bought a new driveshaft. I have a really good Subaru dealer that took care of me when my 98 Legacy's alternator fried itself. Very nice people.

 

I talked them down to 600 bucks on the driveshaft, which is a lot of money but the rebuilt ones I saw were around 400 and I didn't know if I could trust them.

 

Who knows :).

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Eh I bought a new driveshaft. I have a really good Subaru dealer that took care of me when my 98 Legacy's alternator fried itself. Very nice people.

 

I talked them down to 600 bucks on the driveshaft, which is a lot of money but the rebuilt ones I saw were around 400 and I didn't know if I could trust them.

 

Who knows :).

 

I could have gotten you a source for one almost 1/2 that price.

 

http://www.driveshaftspecialist.com/?gclid=CJWX9bujtqECFcRM5QodjSGF_g

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