CV boot or bearing and Knock sensor.

I just got a 99 Legacy GT today, found out it has a torn right front inner CV boot, the previous owner said that it probably needs a wheel bearing and didn't even know about the boot.

 

Could a blown CV boot show the same symptoms as a shot bearing? Just dont wanna buy both if I don't have to.

 

The check engine light is also on and its lulling a Knock Sensor code, anyone know how difficult it would be to swap that out for a new one too?

 

Cheers!

They'd be different noises and symptoms. A bad bearing will cause rotational whirling or whining and a bad cv will cause clunking or binding on acceleration or while turning. The knock sensor can be done in 20 mins with a 14mm ratchet. It's kind of tricky to get at and it helps to remove the air box on the throttle body but it isn't necessary.

Its a 12mm and you need at least a 6"extension ( 9-12 would be better) to reach down. Note the orientation of the plug wire. Put new in the same way.

O.

Thanks for the replies y'all, I definitely need a new bearing and a new inner CV. Just don't know if I need the boot or the joint yet.

 

Also I read in another forum that the knock sensor could also just be giving me an engine light because I either need to replace my MAF or I need to put premium fuel in.

 

Unfortunately i just filled up 2 days ago so I'm going to be waiting to put premium in.

You definitely need premium. What's the highest you can get where you live?

 

As for the CV boot, as another poster mentioned, listen for noises. Clicking and grating will be indicative of a bad CV joint. If the boot is torn you will need a new one and you might as well refresh the joint while you're in there as the process is the same.

You don't NEED premium.

The USDM 2.5/2.2 NA cars were designed to run on 87 Octane.(except the 96 2.5 which required 91)

It'd be a waste of good money.

Knock sensors are cheap. Or you can pull one off a car in a pick and pull.

 

O.

Didn't you say in another thread that this car was engine swapped? What year and engine are you running if it's different from the 99GT stock?

Sorry for the late reply! Had a super busy week and a bit.

 

I replaced the knock sensor and cleaned up the contact surface while I was at it, car runs like a charm now.

 

I put 91 in just to be sure and it runs better to be honest. No signs of any sort of knocking or pinging and the check engine light is gone.

 

Now just to replace the front left wheel bearing and the right front CV axle, the boot was torn apart and there are rocks and sand in there.

 

Also last but not least, I'm brand new to the forums so no I didn't post in another thread that this vehicle is engine swapped. It has the EJ25D from factory.

 

Thanks for the assistance everyone!

Good to hear.

Spray the bolts for the hub now to let the penetrant work.

May need a pipe to get extra leverage to break that axle nut loose. 32mm/ 1 1/4" .

 

O.

Sorry for the late reply! Had a super busy week and a bit.

 

I replaced the knock sensor and cleaned up the contact surface while I was at it, car runs like a charm now.

 

I put 91 in just to be sure and it runs better to be honest. No signs of any sort of knocking or pinging and the check engine light is gone.

 

Now just to replace the front left wheel bearing and the right front CV axle, the boot was torn apart and there are rocks and sand in there.

 

Also last but not least, I'm brand new to the forums so no I didn't post in another thread that this vehicle is engine swapped. It has the EJ25D from factory.

 

Thanks for the assistance everyone!

 

Your car isn't running any differently whether you run 87 or 93 fyi.

Start saving for head gaskets and timing belt/water pump btw