Ok, everyone. I got back from the 1500 mile trip last week and now I have a few questions/problems with my 2000 limited 3.4 4runner.

1: ever since I got back I have noticed a large decrease in power. It just does not have the pep it did before. It runs fine (although the idle may be a little rougher that before but it is hard to tell). And I used to be able to make the tires ?squeak? when at the stop sign by my house. Now even in the rain they will barly spin at all. It used to be that I would hydroplane with even a little too much gas in the rain. So I know that it is not just me that is off here.

2: there is a noise by the brake booster as close as I can tell. It is a sucking sound. I heard it a few time before the trip but while in there for so long I heard it even more. It sounds kinda like the pcv valve if you take that off while it is running but a lot quieter. Is that normal? It doesn?t do it all the time and I can?t tell what makes it do it.

3: the exhaust seems to be ?smokier? (not that it smoked before, just the normal smoke from the exhaust) then before the trip. But that could be partly due to the rain that has been here and the very high humidity.

I am at a loss as to what could have caused the power loss. It didn?t use a drop of oil the whole trip and all the fluids were changes just before going. We were towing an overloaded trailer up there (not near as bad back) and it had to work but nothing outrages. Thanks for any help, I want to make sure that it is in tip top shape before I drive it around anymore.

 

Pull the plugs and check them, maybe they got burnt.

 

That is possible, that would cause that much power loss over such a short pirod?

I am running an MSD (a full write up and show off thread is coming soon), and i know they are running hot. But they were also brand new 3 weeks ago.

I will pull them as soon as the rain stops. Thanks for the suggestion!

Any other ideas?

 

I would change the oil, mine ran so much better after I towed a trailer 1,000 miles and changed the oil after the trip. The noise you describe sounds like a vacuum leak somewhere. An easy way to check for a vacuum leak is to take a can of brake cleaner while the engine is idling and spray it along all your vacuum lines and connections, if you find a spot that causes a change in the idle when you spray the brake clean on it, thats your leak. Like stated above, the plugs sound like a good starting point. What I would start with in if it were my truck is

-new oil/filter
-check spark plugs and maybe replace them anyways
-check tranny fluid
-search for a vacuum leak
-reset the computer by unhooking the battery and let the computer re-learn your driving habits without a load behind the truck.
-make sure your MAF sensor looks good

 

Also make sure your O2 exhaust sensor/s don't have a lot of build up on them.

 

Yeah, those all sound good. i will try all of that after the rain stops (it has been raining non-stop lately!). What had me puzzeled is that i changed ALL the fluids and did all of the above just before leaveing so it is kind of hard to figure out what could have changed in that short time. I am going to do a compression test as soon as i get the tester and i need to find a good but cheap code reader as well.

I sure hope it is something simple!

Thanks for the help.

 

Do you have a tranny cooler on that thing. IF not, I would check the tranny fluid too to see if it is roasted.

 

You said you can hear a hissing noise by the brake booster, investigate that with some carb cleaner, if the engine races you have a vacuum leak around there. Could be that a hose has a crack in it, booster itself is screwed.

 

Yep got a cooler on it, and the fulid looks fine. I checked all of that right after getting back. I was kinda amazed that it didn't ues a drop of anything after all that (i have only had it for a few months). I am going to be changing the oil and tranny fuid as well though.

Well all the hoses are brand new but that is a possibilty. I sure hope the booster is ok as i really don't want to have to replace that right now. Won't the carb cleaner ruin the hoses? guess not but just seems like if it will eat a plastic glove in seconds it won't do them any good.

 

Tranny cooler so im assuming automatic?

Does it feel like the engine just isnt peppy or like something slipping? I could tell pretty easily when my clutch was slipping (not really THAT noticeable) but by ear knowing the engine's rpm compared to what I'm used to when i release the clutch..

just a thought

 

The hissing sound is normal for the 4runner.... i was concerned about mine when i got it but was told that its a normal thing. If you are looking for a code reader just take it up to Auto Zone or your equivalent and they will run codes for free,

 

Yeah could not find a 5-speed SR5 when i was looking for 6 months so i ended up having to go with the limited and the auto . I wanted the 5-spd though. And yeah i though this same thing and i also know what i usually feel at XX rpm and it has changed. It takes a lot longer to rev up now, in park i can tell a few second differnce to hit about 5k rpm then it used to take. thanks for the suggestion!


Thanks for that point! I had thought there was someplace that would do that but could not remember if it was free of not and if i had to pay i was just going to buy one. I will stop by there this weekend.

And i am glad that is normal, it didn't seem to really be something wrong but didn't sound right either.

 

No carb cleaner is fine for hoses, brake clean however isn't. I'm pretty new to the Toyota truck scene, but hissing doesn't seem like it should be a normal sound.

 

Yeah, but as said above it looks like that is a normal sound for the 4runner.

I am still going to test it but if it passes that i assume it is fine.