wierd vibration
11-30-2018 | 07:16 PM
#1
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wierd vibration
so I bought a 2005 rx8 AT a couple of weeks ago knowing I was going to need an engine due to hot start issues. Compression test confirmed this and mazda rebuilt is on the way. i drove this car home about 110 mile trip, at the time I know it also needed tires, one was completly flat when I arrived there and all 4 tires were all different. On the drive home it did good until I hit the freeway, the first say 10 minutes on the freeway it felt fine after that I started feeling what felt to me like a wheel hop, like a wheel vibrating out of balance. I attributed it to the tires. So I swapped tires a couple of days latter and it did get better but not great, so I had the new ones rebalanced and moved front to back. Soo, today I took it out to test again and sure enough it was fine for the first two freeway stops, then I started feeling the vibration. Again maybe it is a bent wheel, but it feels like it is comming from the rear, from the middle but maybe out to the passenger side, worse under load. I cannot reproduce it if I am not on the freewey, usually starts over 72mph, but if I am at 65 and then step on it to where there is load it vibrates. I understand it might be a bent wheel, but anyone have other ideas? I ask because if it could be the transmission then I would swap it with the engine. BTW mine is a auto tranny. I had something similar on a bmw 325 that had a circular driveshat mount that whent around the rear section of the driveshaft. It had gone bad. The only thing I can think of in the transmission is if the overdrive belt is going bad or maybe the torque converter? I do plan on draining the AT fluid when swapping the engine as it is dark. Ideas please
11-30-2018 | 10:41 PM
#2
I would check all 4 wheels for play in up-down, left-right and in-out directions. There should not be any. If you have a loose link or balljoint you will find it this way.
Whether its the trans or driveshaft - we're all guessing until you get it on a lift and check for play or damage.
Whether its the trans or driveshaft - we're all guessing until you get it on a lift and check for play or damage.
12-02-2018 | 12:20 PM
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it will be checked over tomorrow. If it is just a wheel I will be happy, my main concern is that it has nothing to do with the transmission as the new engine is going in this week and that would be the time to swap the transmission if it was the issue. The only reason I am worried about the transmission is when i get on the freeway the vibration does not start immediatly, it takes a couple of miles, I guess it might be the time it takes for the tires and the air in the tires to warm up, but I worry it could be something to do with the overdrive in the transmission once the transmission fluid is fully warm?? But again, it only does it on the freeway, I cannot reproduce it in town, I have to be on the freeway at higher speeds for a couple of miles
12-02-2018 | 01:04 PM
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From: NYC
Weird (not "wierd" vibration)
So I bought a 2005 RX-8 AT a couple of weeks ago knowing I was going to need an engine due to hot start issues. Compression test confirmed this and a Mazda rebuild is on the way. I drove this car home on about a 110 mile trip, knowing it also needed tires; one was flat when I arrived home and all four tires were at different pressures. On the drive home it did well until I hit the freeway. The first, say, 10 minutes felt fine, but after that I started feeling what felt to me like wheel hop, like a wheel vibrating out of balance. I attributed this to the tires. So I swapped the tires a couple of days later and it did get better – but not great. So I had the new ones rebalanced and moved from front to back. So today I took it out to test it again and, sure enough, it was fine for the first two freeway stops, but then I started feeling the vibration. Again, maybe it's a bent wheel, but it feels like it's coming from the rear, from the middle but perhaps out towards the passenger side; it's worse under load. I cannot reproduce this if I am not on the freewey. Usually it starts at over 72mph, but if I'm at 65 and then step on it, to where there's load, it vibrates. I understand it might be a bent wheel, but does anyone have other ideas? I ask because if it could be the transmission then I would swap it along with the engine. BTW, mine has an auto tranny. (I had something similar on a BMW 325 that had a circular driveshaft mount that went around the rear section of the driveshaft. It had gone bad.) The only thing I can think of in the transmission is if the overdrive belt is going bad – or perhaps the torque converter? I do plan on draining the AT fluid when swapping the engine as it is dark. Ideas, please.
Last edited by New Yorker; 12-02-2018 at 01:15 PM.
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NotAPreppie (12-03-2018)
12-02-2018 | 01:11 PM
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Hey New Yorker, if you want to get all high and almighty that is fine. However you should head your own advice then. "Hint: capitalizing and punctuation are worth" is not correct," capitalizing and punctuating" might be....
12-02-2018 | 01:40 PM
#7
Little-known fact: correcting another member's grammar on RX8 club restores 1 point of compression, distributed evenly to everyone on the thread.
So, jumping into short threads to correct grammar is the best way to help the OP and yourself maintain their engine.
So, jumping into short threads to correct grammar is the best way to help the OP and yourself maintain their engine.
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12-03-2018 | 08:14 AM
#8
What am I doing here?
Joined: Mar 2006
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From: 2017 Miata RF Launch Edition
You want help but you don't want to make it easy for people to help you. Not only that, but you don't want people to help you get more help.
Nobody was getting high and mighty. He even said, "So nothing personal – just a tip! It'll make communicating with others in this country way easier for you."
This isn't about shitting on you. This is about helping you get the help you need. Check your ego at the door or go somewhere else for help.
I would add to New Yorker's advice by saying that paragraphs also make your posts easier to read by eliminating the "wall of text" effect. Again, nobody is trying to give you ****; we're just trying to make it easier for everybody to help you.
Your issues could also be related to shocks, alignment, improper aftermarket wheel installation (if you don't use hub rings you have to do it properly or you'll get vibrations).
Are you getting any vibration in the wheel?
Where are you located and did a previous owner install oil-filled shocks (generally performance aftermarket units found in good coilovers)? If it's cold outside, oil-filled shocks will change behavior (feel really stiff) until they've warmed up. This changes how they behave and could be another explanation for why there's a time dependence to the vibration.
Our drive shafts don't have a yoke or intermediate bearing. They go straight from the gearbox to the diff with nothing in between.
Last edited by NotAPreppie; 12-03-2018 at 08:26 AM.
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