Temperature related transmission whine

I have a '95 Toyota Corolla GLI with a 4 speed automatic transmission. Lately, it has developed a low pitched whine under load (acceleration, climbing a hill), which I suspect is from the transmission. The noise comes on at around 2200-2500 rpm, only at a certain temperature range. When the engine is cold, no noise. After 20-25 minutes drive, noise appears, very audible. With engine/tranny hot (after some 40-45 minutes drive), noise is gone. Any help will be greately appreciated.

Reply to
Dan
Loading thread data ...

Was the transaxle, accessory drive belts, timing belt, etc. serviced recently?

Check the transmission fluid and see if it looks red and is translucent or is brown and smells burnt. If it is the latter, have the fluid replaced.

Noises are very difficult to diagnose without actually hearing them. My recommendation is to have a pro ride with you to hear it.

Reply to
Ray O

None of the above servicing has been performed recently, but there was some body repair after accident that caused damage in front. Tranny fluid is ok. At the shop I've been told noise may come from one of the accessories (water pump, alternator), but this doesn't make sense since noise is there only under load.

Reply to
drnwnr

Actually, it makes very good sense. Alternators often whine under load, but this is unlikely to be your problem. It could be the power steering pump (check the level), or the cam belt tensioner bearing. At the very least the various belts should be checked for wear and damage. Does your engine have a two piece front pulley? If so it could be separating.

You say the trans fluid is OK. How do you know this?

Stewart DIBBS

Reply to
Stewart DIBBS

Can you explain why a belt tensioner or other accessory bearing may whine only when accelerating or going uphill and not in idle? What exactly is a "two piece front pulley"? It's an automatic tranny, so it's easy to check fluid condition (with dipstick).

Reply to
Dan

When accelerating or going uphill, the engine is producing more torque than at idle.

Reply to
Ray O

(acceleration,

Hard to be certain but it will be one of two things, the front pump or the torque converter and in that order would be my guess.

Reply to
SnoMan

Last winter a tranny of mine developed a slight noisy like this, it was a GM 4L80E, (and the only tranny problem I have ever had in 30 plus years too) and they replaced the torque converter and the front pump at no cost to me and said that they have had a few problem with them. Tranny still worked fine and likley would have continued to work too and it was not a loud noise either. Anyway after the parts change, the noise was gone and has not returned.

Reply to
SnoMan

I'm trying to figure out how (and if) a front collision could have caused tranny damage like this. Before the accident there was no noise. The transmission wasn't directly hit in the accident (radiator, bumper and hood had to be replaced). Could it be related to a slightly bent chassis or out of spec front alignment?

Reply to
Dan

When you are looking for advice or information, you should include all the facts up front so you don't get irrelevant information. Has the car been fixed yet?

A slightly bent chassis our out-of-alignment condition is unlikely to cause a transmission whine although either condition can cause premature or uneven tire wear. A reputable body shop will check chassis and suspension alignment during repair.

I don't remember the design of your particular car but the if one of the half-shafts (driveshafts) has a center support bearing that is way out of alignment, the bearing in it could make noises. A little bit of mis-alignment on the support bearing shouldn't make noise.

It is possible that front-end damage could cause a power steering fluid leak, or the power steering fluid could be a little low from seepage over time. A low fluid level in your power steering reservoir will cause it to make a moaning/whining sound.

An over-tightened belt can make the bearings in your air conditioner compressor, power steering pump, and/or alternator wear more quickly, which would make moaning/whining noises.

Noises are difficult to diagnose without hearing. I recommend that you take the car for professional diagnosis.

Reply to
Ray O

He did in another post. I suggested pinched trans cooler line(s). That wasn't it. I was out of good ideas at that point.

They don't. The passenger axle is just a regular CV shaft but longer.

Yup.

Yup.

Yup.

Reply to
Comboverfish

The Field Technical Specialist I used to work with at the S.F. Region was hard of hearing, due to time spent in a foxhole at Guadalcanal. (He used to joke about the irony of working for a Japanese company after surviving that battle). This guy could fix anything but noises - he'd always say he didn't hear anything.

Reply to
Ray O

Thanks all for the inputs. Haven't found the noise source yet. I've been at several shops and have been told that they don't know where this noise is coming from, but it is probably not transmission related. And that it will take a lot of work just to pinpoint it. Oh, well, I guess I'll just have to live with it... I'm just wondering what part could make such a noise only when hot and why?

Reply to
Dan

If it is a whine that gets worse with tempature you are looking at the power steering pump or tranny front pump. They both can make noise for quite some time before they fail. A tranny pump noise is hard to locate in a FWD car because everything is together in one package more or less.

Reply to
SnoMan

There were numerous posts offering numerous suggestions. Some possibilities are power steering pump, alternator, AC compressor, water pump, pulley, and, depending on the model, hydraulic cooling fan.

Reply to
Ray O

I had a GM with a transmission that failed at about 100,000 miles. After rebuild, the tranny always whined. The rebuilders didnt know why, nor did it fail.

In the van I drive now, the tranny whines when it is cold and in reverse, but at no other time. There is a TSB on this, and it turns out it is a valve that is vibrating. Apparently not a serious problem, but I will change it out when I have nothing better to do.

The point is, your noise may be difficult or impossible to find even if they tear the tranny down. I would keep an eye on my fluid condition, service at recommended intervals, and not worry too much until you get some symptoms that the operation is compromised.

Best regards

Reply to
<HLS

My guess is that they did not replace front pump or replaced it with a low quality unit. There is two senerios here, the tranny shop is clueless because they do not know what they are doing or they know what it is but do not what to tell you that your new rebuilt job included a defective pump that they do not want to replace.

Reply to
SnoMan

Well, it could be, but I don't think so. I put another 100 k on the car after the overhaul and never had any indication of a subsequent problem but that little whine.

Reply to
<HLS

Anyone had experience with synthetic ATF eliminating/reducing tranny noises?

Reply to
Dan

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.