Possible Valve Issue but not 100% Convinced

Hi all! Just have a question. Is it normal for the later 2004 2.7L 3RZ-FE engines to have a bit of a gargle/puffy exhaust note to them??? Reason i ask is sometime when my truck sits and idles every once in a while ill hear a pronounced low puff out of the exhaust pipe and it sounds almost like a miss fire. If i rev the engine to say 2000 RPMs and hold it there i can hear the exhaust piff and puff erratically. Like theirs no consistency to it at all. If i sit in my truck i can slightly feel the truck hit and when it hits it makes that pronounced puff out the exhaust. I thought it was a miss fire but i dont think it hits hard enough for it to be a miss fire, though i could be wrong hence why im asking. Not sure if its just the nature of this engine.


Do any of your 2.7L idle kinda like what i described or are they supposed to run smooth as silk like the 5VZ-FE V6 engines?

If this is not a normal occurrence with these engines would a burnt valve cause this problem or out of adjusted valves?

Also what kind of symptoms does a burnt valve give and why does it happen?

 

Ok so I did the so called paper test on the exhaust pipe and as far as I can tell the paper did not get sucked back into the tailpipe... It kept pushing the paper away and even when I just let the paper flap freely it did not go back in. But for some reason every few seconds the exhaust gives like an extra strong louder then normal puff. That being said is it still possible my valves could be out of wack? IV never had the valves checked or adjusted because IV heard that with these trucks its a rarity that the valves ever need to be tampered with. Am I wrong or should I just bit the bullet and have Toyota check them? Any feedback would be great

 

I don't know how much of a response you will get on this topic but with that engine it's not a bad idea to get the valve lash checked. How many miles do you have on the engine?
I am always wondering about the burnt valve issue with this engine. I've had mine checked at 150k and again at 170k and both times have been told that they were in spec.

 

I currently have a little over 99500. I bought the truck with 58000 miles and never had the valve lash done. I'd like to check them myself but if they are out of spec I don't have the cam tool to do it and the time to do it... Who and how much did they charge u for the valve check? I called Toyota today and they quoted me $376.00 to check and adjust them... That price is not including parts

 

I think I paid around $270 that was only for the check and maybe a new valve cover gasket. I think new shims are around $9 a piece.
I don't know what your financial situation is but it might make you feel better to have them checked. Every engine is different. Some 3rz might not need a valve adjustment well into 400k miles where another one might need it at 60k.

 

I would check the easy stuff 1st; inspecting the spark plugs can give you a lot of clues of whats going on in your engine. I'd check the ignition system 1st because it's the easiest, maybe 1 of your coils are going. Could also be a bad fuel injector; intermittent firing, leaking injector, or poor spray pattern. I don't think it's fuel press, but since it's really easy, I'd remove the vacuum line off of fuel pressure regulator to make sure the diaphragm isn't ruptured. Then I'd do a compression test.

If it is a mechanical issue (valves), it will do it (miss fire/back fire) all the time. Your problem sounds intermittent.

 

That's what I kinda figured that if it was mechanical it would be a constant problem and not intermittent. I'm pretty particular about maintenance on my truck and everything gets addressed at the right intervals except the valves because um not sure how to go about the procedure. My plugs have been replaces along with air filter, fuel filter will need it soon. I thought maybe it could be the IAC getting gummed up because I notice that when I come to a complete stop at a light the rpms will hover close to 1000rpms for about 4-5 seconds then drop back down to normal idle speed. Not sure she it does this but I know its normal for these trucks. But when the idle drops back down to normal is when it wants to run a little rough.

 

The company I work for has had several 2.4L 1st gen Tacomas. Not quite the same engine, but similar.....I believe. Anyway, we had one burn a valve at around 120K, I believe it was an 01. We had an 02 go 185K and was running great when sold (boss sells them around 150-200K). We had 150K on the 04 when it was sold, no problems.

I remember reading that there was a problem with one year "tuliping" valves. There wasn't a good reason for the 01 to have performed differently than the other two trucks, same care and feeding.

I had an 86 Toyota with the 22R 2.4L engine. There was an incident involving a mechanic who did not know what he was doing and set the valve clearances near zero clearance (tight!). The result was uneven compression with one particular cylinder being 30psi low when compared with the others. It was the tightest, the valve actually wasn't closing all the way, the others were barely closing, if that makes sense. The immediate clue that there was a problem was the stick shift shaking at idle. It was very noticeable. When running well, these 4cyls will have just a slight vibration at the stick shift, it will not flip side to side, just vibrate.

It seems to me that most 4cyls I have paid any attention to will have a bit of a pop to the exhaust when at idle.

Another clue you have a miss is that the vehicle will fail smog due to very high hydrocarbons at idle. Mine was off the map on the 86 while all this was going on. It destroyed the catalytic convertor over the course of about 800 miles before I figured out what was going on. It ran fine off idle.

 

If you have a missfire, you will most likely have a check engine light on. Any CEL lit up?

 

A quick double check for a ign missfire,,for us guys with plug wires, is a timing light. Clip the pickup on each lead, rev the motor,,see if the light misses a pulse and listen. Read your plugs.

A completely dark shop, with the engine running and revved, will show voltage arc if there is one. Don't get zapped by it,,because it will knock you on your knees,,lol.

Leakdown test for a burnt valve or collapsed rings,,and general cylinder health percentage.

 

OP, you're worrying too much about this.

Checking valves on the 2.7L is pretty simple - just buy a $5 valve feeler gauge and pull the valve cover. I forget the exact process, but you got to put #1 cyl at TDC by rotating the crank to check the virst set of valves.

Buy a $15 haynes manual for the exact process and specs. If they are in spec, it will put your mind at ease. If not, then you can worry about taking it in to the shop.

Also as you do this, throw some new plugs in there and that may smooth out your idle as well.

 

Best advice yet.

It's not gonna take much to check them, the real work is the adjustment.

 

Took it to Toyota and had them do the valve adjustment with compression check. They only charged me $260.00 and that price included a free 2013 Camry rental and a car wash. Compression check was Cyl.#1 163, Cyl.#2 162, Cyl.#3 158 and Cyl#4 162. The valves werent that much out of spec but still needed to be adjusted. Intake side needed it more then the exhaust side. Now i have piece of mind and know that my engine is healthy and in tune. One thing the Tech did mention was for me to remove the throttle body and IAC and give them a good cleaning. Which would also attribute to a rough idle. So im going to go all out and pull both the intake plenum and runners and give them a good cleaning. Then install a catch can.