Why is it sluggish in drive?

some engines bend valves when the belt blows do a compression test

Has the timing belt or chain ever been replaced?

I would suggest a total tune up including replacement of the timing belt. This should get rid of the sluggishness you are experiencing. The replacement of the timing belt is not the major dilemma that it sounds like - they should be changed periodically to prevent failure and more costly repairs.

I suggest the valve timing is out just a little bit. The engine will still run, but it WILL be sluggish!

Your problem is pointing to the alternator. Since you say the alternator is only a year old, the I would check the tension on the belt (deflection should be about 1/2 an inch), and the belt itself. Your problem most likely lies in either the belt, belt tensioner (if applicable), or alternator.

Find out the Code that put the check engine light on first before worrying about the timing belt.A parts house may preform the scan for free. Then you will know how to proceed.

sounds like your timing is out if timing belt has not been serviced in last100000 km then it it possible that you have jumped a tooth on timing belt which means you should stop driving it before it jumps again and does damage to engine

Tell us who made that belt so we can stay away from them.

check engine light on 2004 RAV4

Hi

Timing belts are a critical component and the cost of replacement shouldn't really be means tested against the cost of the car, so if the garage is absolutely sure thats what the problem is then it is definitely worth getting it done without a shadow of a doubt.

As far as the overheating in traffic is concerned, is the cooling fan kicking in? If not then maybe the thermoswitch needs replacing.

Depending on the age of the vehicle (pre or post 1996), it could be fitted with an inercooler, and once again, age dependant, it could be fitted witha MAF sensor.

A blockage or leak in the intercooler or its hoses could cause sluggishness and overheating. Check that the hoses aren't clogged with oil. There will be oil in there, thats normal, but it shouldn't be so much that its narrowing the hoses. A blocked intercooler is a bit more difficult for the layman to diagnose without actually fitting another one.

A fault with the MAF sensor could cause sluggishness. Disconnect the wiring plug and see what happens. If power is restored then the MAF is dirty or faulty. It can be cleaned by removing it and then spraying brake cleaner or switch cleaner onto the hotwire hanging down inside it, and then gently blowing it dry with your breath, but don't physically touch the wire with anything, just spray it and blow on it.

An intake system air leak can also cause sluggish performance and overheating on MAF equipped engines, because it will allow unmetered air into the intake which the MAF doesn't know about and therefor underfuelling ensues, which will cause sluggish performance, and if severe enough, overheating.

There is a solenoid on the side of the fuel pump which is a known cause of sluggish performance on these engines when it fails, which can only really be tested by either fitting another one or using relevant test equipment.

If the wastegate actuator spring has weakened then the wastegate will open way too soon and the result will be no boost and therefor sluggish performance. To check for this, simply pull the vacuum pipe from the back of the wastegate actuator and plug it so it doesn't lose any boost into the engine bay, and then very carefully drive the car and see if it performs any better, but don't use full throttle in case you over boost it because the wastegate will open too late with the pipe removed.

I think I've given you enough to keep you busy for a while!!

Regards

Geordie