I am at my wits end !!! ES300 2003, engine had some sludge to start out with and smoking every others day at the valve covers, I replaced them new. Removed pan and re-placed the pickup oil tube, Re-placed the oil pump new , water pump new, all belts timming, superentine belts, installed new 02 oxygen sensor upstream at firewall. Removed caps and checked all bearings , Cams , rods, mains all look great. NOW THE PROBLEM : Start the car runs great when cold, no noise very smooth , then Eng gets up to Temp , but still reading cool on the dash gauge about half way , THAN the oil light starts to flicker and alittle bit of ticking sound starts runs like crap. Acts like back pressure with not much air coming out of tail pipe. NOW I pulled the exhaust and 3 Cats, And they are clear and open , put air through each and ran water through each and water and air runs out fast and clear . The bottom end was clean and all bearings look good 103,000 miles on car . New PVC valve, new anti freeze ( red lexus stuff) Lexus oil filter \oil . I give up !!!!! I was thinking thermostat but running out of ideas. Any help would be great. Heads are good. Runs great cold , then gets hot , then problems . THanks Dean

 

Sounds like it might have a bad coolant temp sensor. Have you checked for codes?

 

NO I havent checked them . the amazing thing is the check engine light has never come on . But I will check tomorrow , I need to buy a code machine

 

Where is the coolant temp sensor located . I will look into it tomorrow . Thanks !!! I will sure give it a try , getting very flustrated now . lol New plugs also and air filter , ran great other than the smoke which is fine now , after cleaning and replacing all mentioned. Runs about 15 mins than gets hot and starts ticking etc. and oil light comes on.

 

Replaced coolant temp sensor ! still have problem . Now noticed the fan is not coming on, car gets hot and I hear a thumping sound , turn on air conditioner both fans run ,cools down and thumping noise goes away. ALso thumping sound goes away when I pull the tube and open a little vaccum leak at the PVC Valve. any ideas out there .

 

How long have you had this car?

 

Since you don't have any problems until you are in the closed loop mode, this could indicate a problem with one of your sensors. Have you checked the MAF sensor? Do you have any error pending or otherwise?

 

I owned the car since new 2003

 

I will be reading the codes tonight , I just replaced the coolant temp sensor , no luck there ! I just bought a code reader . NO I have not checked the MAF sensor yet , . One problem I am not sure of is the fan does not come on , so thinking maybe a sensor there too! Turn on air both fans work , cools down runs good , I dont know at what point in temp the fan should kick on. I will keep you updated as to progress , Now to figure out this code reader . lol I am old school ! . Just started car an hour ago to move out of way . It runs great cold, cant even hear the eng , gets hot then the problems.

 

Hi tom ; Got a code first : P0001 Fuel Volume Regulator Control Circuit open. Than P0174 ( MAF sensor) ? Says System Too Lean bank 2 . Than P0016 Crankshaft \camshaft position correlation bank 1 sensor A . The P0001 code , fuel volume etc . Could that possibly be linked to the Throttle body . ? I cleaned it out with throttle body cleaner lots of carbon ! BUT I also removed the Throttle position sensor , and may not have installed it back in right . I did mark it but I could not tell if the Flap or ( butterfly was open slighty or closed due to the carbon buildup ) could this be what is meant by an open fuel circut.. and if so would the throttle position sensor affect timming , etc . thanks dean

 

This is really beyond my expertise. But the first thing I would do would be to clean the MAF. It's easy and can't hurt. Other than that, I can't help. Sorry. If I come across anything I'll let you know.

 

Did this problem occur after you changed the timing belt? According to another site this might mean the belt is off by a tooth.

see http://www.2carpros.com/questions/to...0016-amp-p0018

 

After more research, if this occurred after a timing belt change, check to make sure you got the belt on correctly and timing marks are aligned. I did a search for "P0016 after timing belt change" and got several hits with this error.

 

Clear out all your codes and see which ones come back first. The open circuit is referring to an electrical issue with the fuel control circuit. Sounds like you are getting a lean misfire, not a good thing as that will overheat the exhaust manifold and it dumps raw fuel into the cat.

 

Tom Yes that was a part of the problem pulled off and the bank 1 cam side was off a tooth , I believed it had jumped earlier. I fixed that problem, than cleaned the MAF sensor, Cleared all codes and started up again . NO light yet ! in that area . NOW this problem : With the Engine running and in park or neuteral I am getting a dead thumping sound. When I put the trans in gear and put a load on it holding the break, the noise goes away and the engine runs quiet. driving me nuts!!!!!!!