6G Celicas Forums

I recently experienced a bizarre situation with my Celica convertible and I would like to hear comments and experiences from other convertible owners.

I have a ’99 Celica convertible that I only drive in summer and it is garaged the rest of the year: It has 57K miles, with brand new tires that were recently spin balanced. I live in suburbia and most of my driving is local, with occasional highway speeds of 65 MPH at most. If it isn’t raining, the top is always down, so I rarely drive with the top up.

I recently drove 200 miles on a trip into the rural countryside. Due to a thunderstorm my car was all wet so I had to drive back with the top up, as the weather was unsettled. The rain had stopped, it was merely cloudy and there was no wind. While driving on an interstate highway at speeds of 75-80 MPH I noticed an unusual vibration in the steering wheel and throughout the entire car. It seemed worse on a downgrade and somewhat better when turning or on level ground. This was very disturbing, as considering the excellent condition of the car and having practically new tires, there was nothing to account for it. The vibration condition continued for 50 miles, during which the sky cleared and the top became dry. I stopped at a rest area and put the top down. I continued my trip, purposely driving at the same relatively high speed – and the vibration disappeared entirely. With the top down, there was NO further vibration whatsoever!

There is only one conclusion I can draw: The convertible top on a ’99 Celica plays havoc with the aerodynamics of the car when driven at higher speeds. My previous convertible, a ’89 Celica didn’t do this – but that car had a much narrower track width and a smaller convertible top.

Comments? Has anyone else noticed this?

I have a 95 vert with 170k miles and have never experienced any vibration....top up or down.

Do you ever drive it at 75-80 with the top up?

I don't recall ever feeling vibration at speeds below 65.

Get it aligned. Mine is perfect

If the alignment were off (or if it were a suspension problem) there would be vibration present whether the top were down or not.

My previous tires were worn evenly for their duration of life, from start to finish. This is obviously not an alignment problem, nor a wheel balancing problem. This only occurs at high speed, and only with the top up. At the same high speeds with the top down there is no vibration present, whatsoever.

Those are the facts, strange as they may seem.

This post has been edited by thymeclock: Jul 23, 2013 - 10:43 PM

You have tested driving top down many, many times... but have only ever experienced the vibrations once with the top up (As far as I can surmise from your comments). Since it is not a phenomenon commonly experienced by others here, you should go for another drive with the top up and see if the problem persists... you may notice something else at the same time that is contributing to the issue!

i routinely hit 80+ on i4 heading in to orlando with the top up and the air on and no vibrations.

My 1999 vert is garage kept and driven for pleasure and long trips. Also has been exposed to various weather conditions -- rain, storms, high winds, etc.

Never have I experienced any vibration or handling problems at low or high speed. In fact, just the opposite -- one of the most stable handling cars I have ever owned!

Question: Was your recent spin balance done because of the vibration or was it done before you noticed the vibration? First place to re-check if done before you noticed the vibration. If it is an alignment problem, then usually a front end gentle rock or sway might occur at low coasting speed. But the balance and alignment are basic items to recheck.

Next item are tires - is one of them "separating or developed a slight bulge in the tread?" This will definitely cause a new vibration!

____________________________________________________________
__________________________

The spin balance was done when the 4 new tires were mounted. The tires are Kumho Ecsta 4X 's. They have about 1K miles on them by now, at most.

As I mentioned, the old tires were worn evenly, so it's not the alignment. While I was experiencing the vibration, of course I thought that the wheel balancing might not have been done properly - but that would not account for the vibration disappearing completely with the top down. (I've been driving for more than 40 years and have owned various convertibles throughout my adult life.)

There is only one other possibility that I can think of. My previous convertible was an '89 Celica that I bought used. I had that car checked by a mechanic before I bought it. After I bought it I noticed weird, unstable handling at speeds of over 50 MPH. The tires that came with it were Dunlops; when I checked the tire pressures I found that the previous owner had them inflated to over 40 PSI. I reduced the pressure to about 30 PSI and the unstable handling problem disappeared. I wasn't happy with the Dunlops and when they needed to be replaced I bought Sumitomo's which worked great, even when overinflated.

Now back to my current '99...

When I put the car on the road in May and installed the new tires, I inflated them to 40 PSI. Over-inflation gives a harder ride, but good MPG, as expected. Considering my previous experience with the Dunlops, this is the only other possibility I can think of that might be the cause. In this case it's not quirky handling, but rather vibration. Some tires have no issues with over-inflation, but some tires (as in the case of the Dunlops) apparently DO. (My wife's car has a cheap set of Kumho tires and shows no handling or vibration issues with their being over-inflated at 40 PSI.)

This link seems to affirm it: click here


After my trip I checked the tire pressures when cold and found them to be at 37 PSI. I have now reduced the pressures to 32 PSI. Unfortunately, since I live in a citified area, I can't drive much faster than 65 anywhere around here - so I won't be able to replicate the conditions of having top up and going 75-80.

It still doesn't explain why the condition disappears when the top is down though. (Which is why I started this thread...)

This post has been edited by thymeclock: Jul 25, 2013 - 1:27 PM

when ur top is down, you dont feel vibration because you are being distracted with all the noise coming from the wind.

Unless u have a serious gap between the car and the top at the front windshield, there is no reason for the top to cause vibration,

No - I was monitoring it carefully and I considered this, but it's not the case.

Read my previous recent post about tire pressures.

I was wondering if, by chance, you didn't have the top front catches completely sealed correctly? I've done this, when in a hurry, and some weird noises happened.

I just replaced my 1997 vert's Bridgestone Potenzas with Kuhmo Ecsta 4x tires. The Bridgestones were worn evenly, but I probably should have had the car aligned. I'm not experiencing any out of alignment symptoms, but they can be subtle, and grow. It's hard to imagine the top causing the steering wheel to vibrate, but it could act like the top of a drum, amplifying any problems with the car. Toyota recommends that the top not be stored down for extended periods. I bought my vet in October 2012, and it felt a little funky after being on a lift twice. It was a very mild feeling, and went away after a few minutes, so I'm going to chalk that up to convertibles not being as rigid as hardtops.

A computerized alignment isn't expensive, and might solve your problem. My niece's fiancée is a mechanic at the local Toyota dealer, so I should swing past tomorrow. They give you a before and after printout of the alignment specs, so I'll let you know if there was anything significant.

Typically vibrations in the steering wheel can not be fixed by a front end alignment. Its usually from out of round tires (could be flat spots since you park it during the winter), tires that need balanced, or something wrong in the front end. Go get your tires balanced and have them shake down the front end while its in the air.

My black car would vibrate with the top up becuase the top wasnt "sealing" very good and the passenger side stuck out a little bit and "caught" air. The white one lines up and seals perfect. No problems out of my white one.

This post has been edited by TRDweaponX: Sep 9, 2013 - 11:53 AM

I've had mine over 100 mph and no vibrations at all. 160k miles on the original suspension and a strut that occasionally knocks and it is still perfectly smooth over 100.

I'm pretty sure your problems will lie elsewhere. The only way I could buy the "aerodynamics..top down..." thing is if the car had been repaired from a serious accident and may have frame damage, even then it's a longshot.

The top weighs between 150 and 200 I would guess, and the weight is displaced when you lower the top, moving some weight from the front suspension to the rear. I would leave the top up and have three friends sit in the back seat (funny I know..no room) then see if the vibration comes back. Or load the trunk with bags of cement or weights. If not then I don't know.

I think this is a problem that happens randomly and it seems it is the aerodynamics, if not then it might be the weight displacement. Otherwise I have no idea.

top isn't that heavy, i've had mine off and was able to lift it rather easily... i would say 40 to 60lbs max

good to know, that's not enough of a weight transfer to make what I said earlier true then.