Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Toyota > Avalon/Pronard
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools
Old 11-09-2010, 02:14 PM   #1
diceccon
AF Newbie
 
Join Date: Nov 2010
Location: East Greenwich, Rhode Island
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Avalon Transmission Problems?

I have a 1998 Toyota Avalon with 75,000 miles and earlier today what sounded like a slipping transmission began. I bought the car about 3,000 miles ago, so changing the transmission fluid wasn't quite present in my mind. While trying to shift, it will lag and eventually make a popping noise. When I rev the engine in neutral, everything sounds fine. The popping sounds like it's coming from the back of the car, but I'm afraid to go out and test it.

What should I do about this? This is my first car and it's pretty vital to my job.
Also, I have insurance, but I don't think that it covers this kind of thing.
diceccon is offline   Reply With Quote
Old 11-10-2010, 09:15 AM   #2
Brian R.
Resident Chemist
 
Brian R.'s Avatar
 
Join Date: Feb 2004
Location: Rockville, Maryland
Posts: 8,586
Thanks: 105
Thanked 157 Times in 157 Posts
Send a message via Yahoo to Brian R.
Re: Avalon Transmission Problems?

Have you changed the transmission fluid?
__________________
Forum Guidelines:http://www.automotiveforums.com/vbulletin/guidelines.html

"What we've got here is a failure to communicate"
Brian R. is offline   Reply With Quote
Old 11-10-2010, 12:29 PM   #3
jdmccright
The RustBuster
 
jdmccright's Avatar
 
Join Date: Feb 2006
Location: La Plata, Maryland
Posts: 2,290
Thanks: 1
Thanked 51 Times in 50 Posts
Re: Avalon Transmission Problems?

First, check the transmission fluid level and its condition. If it is low, look underneath for any leaks. It may have been topped off when you bought it, but leaked out as you drove. If it is still full, then check its color and odor.

Fresh transmission fluid will look a clear red or slightly orangish color. If it looks more pale red, clear, gray, or brown then it is due to be changed. If it has turned opaque, then it has been oxidized due to overuse...definitely time to change it!

Next is its odor. Transmission fluid doesn't smell great when fresh but it does have a distinctive odor compared to engine oil. Buy a quart and take a whiff to get familiar. Overused fluid will have a pungent, burnt smell to accompany its worn out color. Again, this is the sign of fluid left in too long...change it!

If this is your case, I will suggest you do NOT go and have your transmission power flushed in hopes of getting rid of all the bad fluid immediately. This procedure has been known to cause transmission failures shortly thereafter. Instead, have the tech change the fluid and in-pan filter. Drive the car for a few hundred miles, then have the fluid changed again. A few hundred more, and change it again.

Doing it this way allows any built up particles and varnish to slowly be removed or redissolved back into the fluid. Power flushing causes these particles to become dislodged en masse and pushed into the intricate valves, seals and passages inside.

Good luck and let us know how you fare.
__________________
Current Garage:
2009 Honda CR-V EX
2006 Mazda 3i
2004 Chevrolet Silverado 2500HD
2003 GMC Envoy XL
2000 Honda ST1100
2000 Pontiac Sunfire

Vehicle History:
2003 Pontiac Vibe AWD - 1999 Acura Integra GS - 2004 4.7L Dakota Quad Cab 4x4 - 1996 GMC Jimmy 4wd - 1995 Chevrolet C2500 - 1992 Toyota Camry LE 2.2L - 1992 Chevrolet S10 Ext. Cab 4.3L - 1995 Honda ST1100 - 1980 Yamaha XS400 - 1980 Mercury Bobcat.
jdmccright is offline   Reply With Quote
Old 11-10-2010, 01:32 PM   #4
diceccon
AF Newbie
Thread starter
 
Join Date: Nov 2010
Location: East Greenwich, Rhode Island
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Avalon Transmission Problems?

I took it to a mechanic, and after further self-inspection I determined that the problem was more likely the bolt holding the engine in place, which made sense with the various problems due to the shaking upon acceleration. I'll post what it actually is once I find out, but for the moment we're not looking at a transmission problem.
diceccon is offline   Reply With Quote
Old 11-10-2010, 01:39 PM   #5
jdmccright
The RustBuster
 
jdmccright's Avatar
 
Join Date: Feb 2006
Location: La Plata, Maryland
Posts: 2,290
Thanks: 1
Thanked 51 Times in 50 Posts
Re: Avalon Transmission Problems?

It could be a broken engine or transmission mount, but it could also be a broken flywheel flexplate. Let's hope for one of the former.
__________________
Current Garage:
2009 Honda CR-V EX
2006 Mazda 3i
2004 Chevrolet Silverado 2500HD
2003 GMC Envoy XL
2000 Honda ST1100
2000 Pontiac Sunfire

Vehicle History:
2003 Pontiac Vibe AWD - 1999 Acura Integra GS - 2004 4.7L Dakota Quad Cab 4x4 - 1996 GMC Jimmy 4wd - 1995 Chevrolet C2500 - 1992 Toyota Camry LE 2.2L - 1992 Chevrolet S10 Ext. Cab 4.3L - 1995 Honda ST1100 - 1980 Yamaha XS400 - 1980 Mercury Bobcat.
jdmccright is offline   Reply With Quote
Old 11-10-2010, 09:57 PM   #6
diceccon
AF Newbie
Thread starter
 
Join Date: Nov 2010
Location: East Greenwich, Rhode Island
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Avalon Transmission Problems?

Ok, I just got it back from the mechanic's and it turns out the problem was in the ignition system. Apparently the electrical systems for two of the cylinders (out of six) were faulty, and the sparks were not firing. All in all everything cost me $450, though looking at the parts I was charged nearly $10 for a single spark plug, pretty steep but oh well I'm glad to have my car back so quickly.

Why would my car be making deep mechanical popping noises with acceleration and what seemed like trouble switching gears, from only an ignition problem?
diceccon is offline   Reply With Quote
Old 11-11-2010, 07:28 AM   #7
jdmccright
The RustBuster
 
jdmccright's Avatar
 
Join Date: Feb 2006
Location: La Plata, Maryland
Posts: 2,290
Thanks: 1
Thanked 51 Times in 50 Posts
Re: Avalon Transmission Problems?

Yet another case where it is hard to diagnose from afar...a noise can be described a thousand different ways.

I don't know how your engine's electronics are laid specifically, but there are sensors galore to help the engine's computer, called the electronic control module or ECM, keep tabs on what's going on under the hood: how much air is going in, at what temperature and pressure, when to squirt the gas and how long to squirt, firing the spark plugs at the right millisecond when the crankshaft is in just the right position while spinning at 3,000 rpms, then also making sure no fuel is wasted, and any that is is taken care of by the catalytic converter, etc, ad nauseum. In short, it is a complex electronic dance that can easily be disrupted by one malfunctioning part.

In your case, it could have been caused by failing spark plug coils (they can be pricey), though to have two fail at the same time is unusual. But having that happen throws off the timing for the other sensors, notably the vehicle speed sensor and the crankshaft position sensor that helps determine what gear you should be in for the engine speed, load, etc. The ECM will compensate the best it can to continue to allow driver operation albeit at a reduced power, speed, etc., in an attempt to limit any potential for engine damage.

Another possible explanation is that the electrical system that controls your spark plugs may fire more than one plug at a time simultaneously. This doesn't hurt the cylinder getting the extra spark and can help scavenge any leftover fuel. The caveat is that if that circuit fails, you've got not one but two cylinders not working well, if at all.

But we're glad you got an answer and thanks for posting back with the solution.
__________________
Current Garage:
2009 Honda CR-V EX
2006 Mazda 3i
2004 Chevrolet Silverado 2500HD
2003 GMC Envoy XL
2000 Honda ST1100
2000 Pontiac Sunfire

Vehicle History:
2003 Pontiac Vibe AWD - 1999 Acura Integra GS - 2004 4.7L Dakota Quad Cab 4x4 - 1996 GMC Jimmy 4wd - 1995 Chevrolet C2500 - 1992 Toyota Camry LE 2.2L - 1992 Chevrolet S10 Ext. Cab 4.3L - 1995 Honda ST1100 - 1980 Yamaha XS400 - 1980 Mercury Bobcat.

Last edited by jdmccright; 11-11-2010 at 07:30 AM. Reason: typos
jdmccright is offline   Reply With Quote
Old 11-11-2010, 08:34 AM   #8
diceccon
AF Newbie
Thread starter
 
Join Date: Nov 2010
Location: East Greenwich, Rhode Island
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Avalon Transmission Problems?

Thank you very much,
Apparently the car was in need of a major tune-up, I've only just received the car, and with only 75,000 miles I'm guessing that it's never had one. Indeed both of the spark plug coils failed, I have no idea why, but everything's over and it's back to normal, or better than normal because they performed the tune-up.
(You're right on the wasted gas - just before the problem really kicked into gear I was getting a dismal 17 mpg, where it should be getting around 25)
diceccon is offline   Reply With Quote
Old 11-18-2010, 09:51 AM   #9
jdmccright
The RustBuster
 
jdmccright's Avatar
 
Join Date: Feb 2006
Location: La Plata, Maryland
Posts: 2,290
Thanks: 1
Thanked 51 Times in 50 Posts
Re: Avalon Transmission Problems?

If it's likely never had a tune up, then I would highly suggest you consider having the timing belt changed soon if not immediately. I'm not sure of the mileage interval for your car, but 75k miles is up there. Check your owner's manual supplement for the maintanance interval.
__________________
Current Garage:
2009 Honda CR-V EX
2006 Mazda 3i
2004 Chevrolet Silverado 2500HD
2003 GMC Envoy XL
2000 Honda ST1100
2000 Pontiac Sunfire

Vehicle History:
2003 Pontiac Vibe AWD - 1999 Acura Integra GS - 2004 4.7L Dakota Quad Cab 4x4 - 1996 GMC Jimmy 4wd - 1995 Chevrolet C2500 - 1992 Toyota Camry LE 2.2L - 1992 Chevrolet S10 Ext. Cab 4.3L - 1995 Honda ST1100 - 1980 Yamaha XS400 - 1980 Mercury Bobcat.
jdmccright is offline   Reply With Quote
Old 05-24-2013, 09:24 PM   #10
whopperdad
AF Newbie
 
Join Date: Mar 2008
Location: old hickory, Tennessee
Posts: 13
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Avalon Transmission Problems?

Timing belt change is not due until 90,000 miles
whopperdad is offline   Reply With Quote
Old 05-26-2013, 05:07 PM   #11
Brian R.
Resident Chemist
 
Brian R.'s Avatar
 
Join Date: Feb 2004
Location: Rockville, Maryland
Posts: 8,586
Thanks: 105
Thanked 157 Times in 157 Posts
Send a message via Yahoo to Brian R.
Re: Avalon Transmission Problems?

I doubt anyone interested is still reading this thread.
__________________
Forum Guidelines:http://www.automotiveforums.com/vbulletin/guidelines.html

"What we've got here is a failure to communicate"
Brian R. is offline   Reply With Quote
 
Similar Threads
Thread Thread Starter Forum Replies Last Post
Alarmed by website highlighting Honda Odyssey Transmission Problems LibertyLoudSpeaker Odyssey 1 07-09-2010 03:03 PM
2003 GMC Sierra 1500 5.3 Transmission Problem kkaupang Sierra 1 05-19-2010 09:58 PM
1994 Prizm possible transmission problem theginchico Nova | Prizm | Spectrum | Sprint 0 04-11-2010 12:52 PM
1995 3000GT Turbo manual transmission problem rene8603 3000GT/Stealth 8 10-08-2009 03:49 PM
Transmission Problem SeanCL Cobalt 3 09-15-2009 08:16 AM

Reply

POST REPLY TO THIS THREAD


Tags
avalon , slipping , toyota , transmission
Go Back   Automotive Forums .com Car Chat > Toyota > Avalon/Pronard

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 05:35 AM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts