Help With Rx300

[mrchinky714]

Hey guys, I have a problem with my 2000 Lexus RX300. It has 115k miles on it and yesterday the check engine light came on. It also began shaking violently even on start up. The Idle RPM stays at 1500 and above even after letting the car warm up. I bought an OBDII reader and it says "error 0300 Random" and P0304 misfire cylinder 4 and P0305 misfire cylinder 5. I have done some searching to see if anyone else has this problem and i read a few post about people who has had misfire cylinder but it turns out to be the coil pack or something else. What do you think the odds are in my case that the misfire is due to a bad spark plug? or do you belive the coil packs to be the problem? The dealership quoted me at 342.14 for the spark plugs and 102$ each for each coil pack which seems outrageous.

[lenore]

The coil packs could be switched to see if the code moves, that would tell you for sure....Here is diagram of cylinders:

http://autorepair.about.com/library/firing.../bl-fo-3278.htm

You could swap cylinder 4 with 6 coil paks real easily and see if the code moves, If it does the coil pak on 4 is bad....coil pak 5 is a lot harder to get to. As for the plugs Unless they were changed before I seriously doubt they are bad. The original plugs are very good and can easily run 150k miles.

[lenore]

Here is a post on the RX330 which is very similiar.

http://us.lexusownersclub.com/forums/index...mp;#entry346240

[tmastres]

I don't think its plugs but at that mileage there is a remote chance. It seems a bit unlikely that 2 coils would fail at the same time but if I had to bet I would say coils failure over plugs. There was a very similar post to your recently but I don't remember the resolution to it. I agree completely with the idea to swap coils and see if the code moves with it. I also have a 2000 with 115k miles on it and after my 3rd coil failure I finally replaced all the remaining coils. There is a new part number for coils that supercedes the original one: new 90080-19016

old 90019-02234. If its the coils, yes they are expensive. You Should NOT have to pay over $100 for them but they will run $85-90.

[mrchinky714]

thanks for the input guys. I will definitely try to switch the coils. Should i erase the CE codes after switching the coils to see if the new codes show up?

[mrchinky714]

yeah i took a look at the spark plug placement. Dang the 1/3/5 looks like such a pita to do. Does anyone have a guide in which you can get super easy access to them? i don't mind taking out stuff like the air intake box. I just don't want to have to reach around and blindly poke at things. Why didn't toyota make them easy access like the 4runners? :( the 4runner sparks were super easy to get to!

Also thanks tmastres, I will call up the toyota dealership near me to see how much is the coil overs. dirty lexus dealership trying to nickel and dime me. :(

[lenore]

Here is info on removing the air plenum throttle body which will give better access to the rear plugs.

http://www.clublexus.com/forums/rx300-foru...park-plugs.html

[mrchinky714]

Here is info on removing the air plenum throttle body which will give better access to the rear plugs.

http://www.clublexus.com/forums/rx300-foru...park-plugs.html

wow thanks a lot! seems tough still but I will give it a whirl when I see whats wrong with the car tomorrow. Hopefully it is just the spark plugs and not the actual coil packs. But if it is I will probably end up replacing it all; coil packs and spark plugs.

[code58]

Here is info on removing the air plenum throttle body which will give better access to the rear plugs.

http://www.clublexus.com/forums/rx300-foru...park-plugs.html

Good time to give the throttle body and the IACV a good cleaning. Some clean the IACV on the car, a little more work but I prefer to clean it off and know it was done right. The rear plugs aren't easy to get to but I always try to keep myself in a good frame of mind and enjoy the challenge and it'll be over before you know it and you can bask in the satisfaction of knowing you've accomplished more than one thing (saving quite a bit of money not the least of it).

[mrchinky714]

Here is info on removing the air plenum throttle body which will give better access to the rear plugs.

http://www.clublexus.com/forums/rx300-foru...park-plugs.html

Good time to give the throttle body and the IACV a good cleaning. Some clean the IACV on the car, a little more work but I prefer to clean it off and know it was done right. The rear plugs aren't easy to get to but I always try to keep myself in a good frame of mind and enjoy the challenge and it'll be over before you know it and you can bask in the satisfaction of knowing you've accomplished more than one thing (saving quite a bit of money not the least of it).

hey code58 i see you're from the OC as well. Which part if you dont' mind me asking?

[mikey00]

wow thanks a lot! seems tough still but I will give it a whirl when I see whats wrong with the car tomorrow. Hopefully it is just the spark plugs and not the actual coil packs. But if it is I will probably end up replacing it all; coil packs and spark plugs.

Swap the coil packs as already suggested to see if it is the packs or plugs. I can almost guarantee it is not the plugs. Plugs are due to be changed at 120K. But a lot of people run them well over 120K and they still look like new when changed. Mine came out at 130K looking like new. I have heard of a lot of people fixing the misfire problem with new coil packs but never one with bad plugs but there is always that possibility. Just trying to say that the odds are with the packs not the plugs.

[code58]

Here is info on removing the air plenum throttle body which will give better access to the rear plugs.

http://www.clublexus.com/forums/rx300-foru...park-plugs.html

Good time to give the throttle body and the IACV a good cleaning. Some clean the IACV on the car, a little more work but I prefer to clean it off and know it was done right. The rear plugs aren't easy to get to but I always try to keep myself in a good frame of mind and enjoy the challenge and it'll be over before you know it and you can bask in the satisfaction of knowing you've accomplished more than one thing (saving quite a bit of money not the least of it).

hey code58 i see you're from the OC as well. Which part if you dont' mind me asking?

Just down the road a skip and a hop- FV. Roger

Concerning the plugs, I did it mostly by feel and though they're a challenge, they're not impossible. I would say that I changed them at 97k on my DIL's RX and they did NOT need changing! Iridium is the hardest metal known to man and it just doesn't wear. I did find them on e-bay and discovered the seller was local (Beach Blvd.) so called and asked if I could come by and pick 'em up- no problem. It was about $48 something plus tax for 6 Denso Iridium, from what I remember. Very little chance it's plugs- very good chance it's COP's

[smooth1]

I read your first post. I don't think it's coil packs as cylinders 4 and 5 both run on different coil packs. It actually sounds more like a fuel injector problem. The seals probably went out. The car is also probably in "limp mode". it's a safety logic programmed into the ECU. That's why it revs the way it does. I would get some rebuilt injectors and just replace them. Then reset the ECU.

[mrchinky714]

thanks for the help guys. I'm going to switch coil packs tomorrow. Been raining on and off all day here and the car is outside didn't want to move it and risk breaking anything. Smooth1 thanks for the tip. Is changing the fuel injectors easier than coil packs? never changed them. Outside of routine maintenance I have done much. Just the usual like audio.

Just an update. I switched the coils on cylinder 4 and 6. Erased the codes using the codekey reader. Started the car and no check engine light. I then drove it for a couple while just to make sure it was gone. Well while driving the check engine light came on and flashed, only this time it didn't stay on. It seems to only flash while i'm gassing the engine going past 2.5K rpm. The car is still shaking some what but not as hard as was before. After driving around the block for about 2-5 minutes I came home and the CE light was still flashing so i turned the engine off leaving it on and plugged in the OBDII reader. 1 Error found P0305, misfire in cylinder 5. Cylinder 4 or 6 didn't show up. What gives? whats making the car act like this, do you guys think its as smooth1 said and it is the fuel injectors? is there any way i can test to see if its the fuel injectors? Also while driving i notice when I don't gas the engine the rpm drops down to 500 rpm or just a little higher like maybe 550 rpm.

[mrchinky714]

okay after driving it for a while the CE light is on this time not coming off. Pulled out the OBDII reader and it says misfiring P0300 random, P0304, and P0305. I already changed the coil pack from cylinder 4 and cylinder 6 so it seems like its something wrong with cylinder 4 and cylinder 5. Any suggestions on what it could be? the car is shaking violently again even from start up and still shaking when driving even after engine has warmed up.

[code58]

okay after driving it for a while the CE light is on this time not coming off. Pulled out the OBDII reader and it says misfiring P0300 random, P0304, and P0305. I already changed the coil pack from cylinder 4 and cylinder 6 so it seems like its something wrong with cylinder 4 and cylinder 5. Any suggestions on what it could be? the car is shaking violently again even from start up and still shaking when driving even after engine has warmed up.

This your neighbor from down the road. Help me out here, I'm confused. Cylinders 4&5 are the cylinders the original codes indicated a problem with. The term "switched the COP's" has pretty much been used by everyone here. Were they "switched" or replaced? It wouldn't do much good to "switch" them if they were both indicated as problematic by code. If they were replaced, that a different story. You can test the COP's, one at a time by removing them, leave it connected to the connector plug and insert a spark plug (used) and run it to observe the spark. DO NOT remove the spark plug from that hole and DO DISCONNECT the plug in on the injector from that hole. You are only observing the spark. (I know, not very scientific, but it does work). After you have determined your COP's are firing steadily, remove the plug on to the injector from the bad cylinders 1 at a time and see if the lack of fuel makes any difference. If it does (and indicates injector problem), I would 1st get a can of CHEVRON INJECTOR CLEANER, the straight stuff, will be anywhere from $7. to $10 for the can and add to about 10 gal. of fuel. If that doesn't clean the injectors out (best stuff ever made for injectors), then it may be time for some rebuilt injectors like smooth1 said. But I don't like throwing parts at a car (can get expensive without fixing the problem) so I'd rather KNOW what I'm doing has a pretty solid chance of fixing the problem. Good Luck!

P.S. Make sure the spark plug is grounded to the engine if you do the COP test.

[mrchinky714]

okay after driving it for a while the CE light is on this time not coming off. Pulled out the OBDII reader and it says misfiring P0300 random, P0304, and P0305. I already changed the coil pack from cylinder 4 and cylinder 6 so it seems like its something wrong with cylinder 4 and cylinder 5. Any suggestions on what it could be? the car is shaking violently again even from start up and still shaking when driving even after engine has warmed up.

This your neighbor from down the road. Help me out here, I'm confused. Cylinders 4&5 are the cylinders the original codes indicated a problem with. The term "switched the COP's" has pretty much been used by everyone here. Were they "switched" or replaced? It wouldn't do much good to "switch" them if they were both indicated as problematic by code. If they were replaced, that a different story. You can test the COP's, one at a time by removing them, leave it connected to the connector plug and insert a spark plug (used) and run it to observe the spark. DO NOT remove the spark plug from that hole and DO DISCONNECT the plug in on the injector from that hole. You are only observing the spark. (I know, not very scientific, but it does work). After you have determined your COP's are firing steadily, remove the plug on to the injector from the bad cylinders 1 at a time and see if the lack of fuel makes any difference. If it does (and indicates injector problem), I would 1st get a can of CHEVRON INJECTOR CLEANER, the straight stuff, will be anywhere from $7. to $10 for the can and add to about 10 gal. of fuel. If that doesn't clean the injectors out (best stuff ever made for injectors), then it may be time for some rebuilt injectors like smooth1 said. But I don't like throwing parts at a car (can get expensive without fixing the problem) so I'd rather KNOW what I'm doing has a pretty solid chance of fixing the problem. Good Luck!

P.S. Make sure the spark plug is grounded to the engine if you do the COP test.

hey thanks for replying code58 i appreciate it. I switched COP on cylinder 4 with cylinder 6 since it was next to each other to see if it was the coil from cylinder 4 that was bad. Cylinder 6 still has no signs of misfire even though the coil from cylinder 4 is still in there. Cylinder 5 was never switched to check because i didn't want to go through all that trouble just to find out it wasn't it when i can test by doing front. I will try to do the fuel injector next to see if those hopefully helps. If not is there a guide on changing the fuel injectors around I can take a look at? Also where would i go about buying a rebuilt injector?

[mrchinky714]

okay i tried the fuel injector and drove around for about 2 hours worth in city stop and go and a little on the high way. Still misfiring. Misfire on cylinder 4 and 5 still. I did get misfire on cylinder 6 but that only happened once, i erased code and drove around some more to see if it would come up again. It didn't.

[code58]

okay i tried the fuel injector and drove around for about 2 hours worth in city stop and go and a little on the high way. Still misfiring. Misfire on cylinder 4 and 5 still. I did get misfire on cylinder 6 but that only happened once, i erased code and drove around some more to see if it would come up again. It didn't.

I would still encourage you to go back and rule out the other things that I enumerated in my last post.

[mrchinky714]

okay i tried the fuel injector and drove around for about 2 hours worth in city stop and go and a little on the high way. Still misfiring. Misfire on cylinder 4 and 5 still. I did get misfire on cylinder 6 but that only happened once, i erased code and drove around some more to see if it would come up again. It didn't.

I would still encourage you to go back and rule out the other things that I enumerated in my last post.

hey code58, sorry i didnt' mention. I tried the fuel injector cleaner, using Redline fuel system cleaner. I drove around for 2 hours and no go. I also tried the spark plug test method using an extra spark plug i had laying around in the garage it made a spark. I even tried replacing the spark plug in the cylinder 4 just incase i accidently over torqued it when i installed and still no go.

[code58]

okay i tried the fuel injector and drove around for about 2 hours worth in city stop and go and a little on the high way. Still misfiring. Misfire on cylinder 4 and 5 still. I did get misfire on cylinder 6 but that only happened once, i erased code and drove around some more to see if it would come up again. It didn't.

I would still encourage you to go back and rule out the other things that I enumerated in my last post.

hey code58, sorry i didnt' mention. I tried the fuel injector cleaner, using Redline fuel system cleaner. I drove around for 2 hours and no go. I also tried the spark plug test method using an extra spark plug i had laying around in the garage it made a spark. I even tried replacing the spark plug in the cylinder 4 just incase i accidently over torqued it when i installed and still no go.

Was it a strong spark or a weak one? A strong spark should be white or blue. A weak one will be yellow. Don't want to get close enough to let that thing bite ya. They've got big teeth. Pull the plug-on for the injectors on the cylinders that are bad (just briefly) then reinstall them, one at a time See if it makes any difference. You seem to have established that it has spark. Fuel is the next logical thing. If it doesn't make any difference it may well be injectors like smooth1 said. If you had a infra red temp gun you can "shoot" the exhaust manifold right where it comes out of the head for each cylinder. On the one or ones that it's running cold or cooler than the others, you know you have a problem. I just hate to see people throw parts at a car only to find out it didn't do the job.

[mrchinky714]

okay i tried the fuel injector and drove around for about 2 hours worth in city stop and go and a little on the high way. Still misfiring. Misfire on cylinder 4 and 5 still. I did get misfire on cylinder 6 but that only happened once, i erased code and drove around some more to see if it would come up again. It didn't.

I would still encourage you to go back and rule out the other things that I enumerated in my last post.

hey code58, sorry i didnt' mention. I tried the fuel injector cleaner, using Redline fuel system cleaner. I drove around for 2 hours and no go. I also tried the spark plug test method using an extra spark plug i had laying around in the garage it made a spark. I even tried replacing the spark plug in the cylinder 4 just incase i accidently over torqued it when i installed and still no go.

Was it a strong spark or a weak one? A strong spark should be white or blue. A weak one will be yellow. Don't want to get close enough to let that thing bite ya. They've got big teeth. Pull the plug-on for the injectors on the cylinders that are bad (just briefly) then reinstall them, one at a time See if it makes any difference. You seem to have established that it has spark. Fuel is the next logical thing. If it doesn't make any difference it may well be injectors like smooth1 said. If you had a infra red temp gun you can "shoot" the exhaust manifold right where it comes out of the head for each cylinder. On the one or ones that it's running cold or cooler than the others, you know you have a problem. I just hate to see people throw parts at a car only to find out it didn't do the job.

Ok, I will try the fuel injector plug and see if that helps. Maybe it could be loose fuel injector. I also plan on testing fuel injector by switching fuel injector of cylinder 6 and 4 to see if 6 will get misfires. I know what you mean, I don't want to waste money by buying parts that aren't wasted especially since a ignition coil cost around $80-105 for one. Is there any guides on here about replacing the fuel injectors on both side? I tried googling RX300 fuel injector replacement. There was a thread over at club lexus but it only had 2 pictures and the guy had to take parts of the intake and plenum out to reach the fuel injector behind. Or if possible is there anywhere that has the service manual for download?

[lenore]

To get the rear fuel injectors you will have to remove the air plenum....see this post for removing plenum it is about knocks sensors but required the removeal of the plenum...

http://us.lexusownersclub.com/forums/index...l=knock+sensors

[mrchinky714]

hey lenore, thanks for the link. Unfortunately that seems like a daunting task. I will most likely need a more specific guide to take it. Would alldata or haynes manual have a more detailed guide? If there is a more detailed guide floating around like lexmex's iacv floating around that would be appreciated. Tried to search the forums and google and got no returns on hits. Infact if you search google this post on the forum is the first link ^_^. Thanks everyone I will be switching the fuel injector on cylinder 4 with cylinder 6 to see if it is indeed the culprit.

[lenore]

The Haynes manual for the Highlander/Lexus RX300 does tell you how to do this.....