[Hummarstra]

Howdy ya'll. Got a 2000 with 142k on her. I'm getting lousy acceleration and I think it's related (maybe) to a noise I'm hearing. I would describe the sound as between a rattle and hiss and it only occurs when I press the gas pedal. At no other time does it make this noise. If I give it gas I hear the noise, if I take my foot off the pedal the noise goes away. It also seems to be most pronounce when accelerating through 2nd gear, though I don't think its gear or tranny related. But, maybe fuel line, injectors, or a vacuum leak. Don't really have the expertise to know, frankly. Anybody know where I should start looking? Thanks!!

 

[paulstoyota]

couple ideas

You can rule out gas line. If that were leaking, the smell would be overwhelming. Hissing - usually a crack in a hose, like a vacuum line like you said. Temperature is a big one too. Do you get the same characteristics when you accelerate with a cold engine vs. an engine up to operating temperature? Look closely, very closely, at all your lines coming off the airbox (as I call it) where the air filter is housed. you can bend them a little bit in your hands and see if there are cracks in the hoses - it'll be hard to see if they go through all the way, but cracks are not good - replace. Make sure your filter is in good shape and hasn't been chewed up by a critter (ive had this happen to me - and to someone I know, only it cost him $1000 to diagnose at a dealer what a rodent did) also, pcv valve? I honestly don't know if there is one or where it is. change that out, they're super cheap.

 

[Hummarstra]

You can rule out gas line. If that were leaking, the smell would be overwhelming. Hissing - usually a crack in a hose, like a vacuum line like you said. Temperature is a big one too. Do you get the same characteristics when you accelerate with a cold engine vs. an engine up to operating temperature? Look closely, very closely, at all your lines coming off the airbox (as I call it) where the air filter is housed. you can bend them a little bit in your hands and see if there are cracks in the hoses - it'll be hard to see if they go through all the way, but cracks are not good - replace. Make sure your filter is in good shape and hasn't been chewed up by a critter (ive had this happen to me - and to someone I know, only it cost him $1000 to diagnose at a dealer what a rodent did) also, pcv valve? I honestly don't know if there is one or where it is. change that out, they're super cheap.

Thanks paulstoyota. I've replaced the PCV and the air filter is pretty good. So ruling those out. I'll closely inspect the hoses like you recommended. Regarding temperature, I think it occurs mostly when the engine is cold and less when it's warmed up. What could that mean?

 

[paulstoyota]

To be honest, I don't know. The last time my car sounded like crap cold, but ran when it warmed up, it was a spark plug wire with a knick in it. Once the engine compartment warmed, it must have closed up or stopped shorting out. But it was missing like mad so it was more than just a noise issue at cold temps. I saw the short when I went out at night in complete darkness, started the car and looked at the engine compartment. Easy to see a short then. Not so sure you have this problem though since you haven't mentioned a coughing engine.

 

[73fxe]

It might be a leak in the exhaust. There are several threads on bad exhaust donuts. A$40-$100 repair.
Rock Auto has it for under $8.00 Scott

 

[KeMBro2012]

I'll second the exhaust leak possibility and highlight it as something to look into for sure. If you read a few of my threads, you'll understand why; d*mn near killed myself.

I'd also check that your intake manifold if properly installed, all the bolts holding it on are torqued correctly, and that the intake manifold gasket is in good condition. this would cause what you're experiencing; it could also be causing your engine to run way too lean, which can lead to all sorts of headaches in short order, so look into that ASAP. I've seen engines eat themselves from the inside out running too lean.

 

[Hummarstra]

Great info, guys. Thanks for all the tips. And I confirmed tonight that its making that sound even when the engine is warmed up.

 

[leakyseals]

A rattle is a mechanical noise (vvt-i, no oil, timing chain, bearings, etc). A hiss is combustion related noise (air intake, exhaust, vacuum leak, hose etc). Your description is both. Means you either have multiple problems or a more accurate description of the noise is required not to make this a complete guess. Happening cold doesn't help much with the noise description. An exhaust leak, vvt-i blockage or vacuum leak could appear and disappear depending on heat.

You've got to narrow the noise description down, make a decision on what your actually hearing. Find the location of the noise under the hood, take a video, etc.

Whats the oil consumption like? type of oil used? Current Level? Check your work from the air filter check and PVC change. Note: aftermarket PVC's with the larger inlet can be noisy, produce a rattle, but should not impact performance.

 

[dward3]

@ Hummarstra, I have a 02 corolla with 153k. I hear those hisses, but its barely noticeable. For your rattling exhaust, it could be just the front heatshield that goes around the front down pipe. I hear the same noises too, lol! :lol:

 

[enoel]

My ''rattling noise'' sound like a ''bad bearing'', it only occurs when accelerating or going up a hill, and goes when I hit 55-60 MPH...

 

[batu8]

I have an 00 VE, 4 Speed Auto, with 323k km (200k miles), had similar experience in the past.

What you have described sounds like a worn out exhaust gasket (donut). The noise sounds like "leak" in the exhaust pipe.

I have replaced the exhaust donut gasket twice w/ after market parts, and once w/ an used OEM part. Dealers here ask for more than $100 for the kit, which include the donut, two bolts and two compression springs.
In my case, the aftermarket did not give as snug of a fit as the OEM. We are looking at $15 for a/m vs. $30 OEM. I will go OEM for sure. The majority of the cost is in the labor.

Based on my memory, this donut gasket is held by two long bolts and two compression springs. In my case, the threads on the two bolts were almost stripped. Consider the heat it has to withstand. I think it'ld be worthwhile to replace them at the same time, if they were never replaced before.

Following link should give you an idea how much the part cost

http://www.toyotapartszone.com/Page_Product/PartDetail.aspx?vinnum=2T1BR12E5YC784402&VAID=3883&productiondate=199908&paintcode=3M5&trimcode=FA40&catalogCode=155440&sectionID=1&isBigPicture=False&componentsID=17-02&componentsIndex=17

If it's the donut gasket, you will need
1 x GASKET, EXHAUST PIPE 17451-22080
2 x BOLT, WASHER BASED H Replaced by: 90080-10291

Try contacting Gary Smith for a quote. He is awesome when it comes to parts.

Hope this help.

 

[batu8]

http://trdforums.com/threads/what-am-i-missing.34805/

This may help.

 

[Sonix]

It might be a leak in the exhaust. There are several threads on bad exhaust donuts. A$40-$100 repair.
Rock Auto has it for under $8.00 Scott

Please, can you link the part and the labor charges?

 

[73fxe]

I do as much of the work on My cars as i can, so I don't know what You would pay to get it fixed. WALKER Part # 31604 Gasket $7.95
http://info.rockauto.com/Walker/112-540.jpg Scott.

 

[Sonix]

I do as much of the work on My cars as i can, so I don't know what You would pay to get it fixed. WALKER Part # 31604 Gasket $7.95
http://info.rockauto.com/Walker/112-540.jpg Scott.

One hundred and 20-30 for parts, and for that you get to hear a mechanic that's saying that he may destroy the manifold, by heating it up! Then it's going to cost you north of $500.00.

 

[qijian]

definitely a exhaust donut gasket leak. I had this problem before and changed out the gasket. 1 hour later and lots of struggle with the spring bolt fixed my problem and sounds good as new!

 

[s049031]

Yep, it's the donut gasket. I had the same issue for months and couldn't figure out what was wrong. After about month of research, I finally decided to replace the gasket. Best $10 I've ever spent.

 

[imgeo]

It could be a loose timing chain:
https://www.toyotanation.com/forum/...1zzfe-timing-chain-tensioner-replacement.html

or it could be a leak/crack/hole in the exhaust manifold ($250 for parts, or $600 fixed at shop). If you smell exhaust fumes from air intake, more likely to be leak in exhaust manifold

 

[THEWISEONE]

Resurrecting a 6 year old post...the OP probably fixed it by then.:surprise: