Sludge motor

Here is a link for you

Post 1997-2001 were the primary engine sludge suspects. However, in

2004 Toyota lowered ALL MODELS' normal oil change intervals from 7500 miles down to 5000 miles. So technically all 1997+ engines are susceptible to oil sludge.

The 2.4L has an even more serious problem. The head bolts can pop loose by themselves, typically in engines > 80K miles. Toyota issued TSB 01507, NHTSA #10021542, Dated April 6 2007 about it. It's a matter of when, not if.

See if you can get a powertrain warranty if it's a dealer sell.

Coolant Loss on 2002-2006 Toyota 2.4L, 2AZFE engines

The following information concerns the loss of coolant on some

2002-2006 Toyota 2.4L, 2AZFE engines. The location of this condition has been noted at the rear of the engine where the cylinder head bolts to the cylinder block. It has been reported that stripped head bolt threads have been found on some of these engines during tear down. When the two rear head bolts lose their clamping ability they allow coolant to seep out at the rear of the cylinder head.

To repair this condition, engine builders report using thread repair tooling used for various GM engines. Specifically, Cadillac 4.6L engines use the same threaded head bolts (Figure 1). The head bolts for this Toyota engine may be reused if they are not damaged and meet the following length specification.

Using a vernier caliper, measure the length of the head bolts from the seat to the end.

Specified bolt length: 6.350=CB=9D to 6.465=CB=9D (161.3 mm to 164.2 mm). I= f the length is greater than the maximum, replace the bolt.

This information was provided by the Engine Builders Association (AERA).

What year did sluge stop being an issue, I thought it was related to toy increasing head temp to reduce pollution.

What year did sluge stop being an issue, I thought it was related to toy increasing head temp to reduce pollution.

******** That isnt exactly what happened.

There may be more than one factors possibly involved:

- The PCV system was changed in some of the affected models, possibly being the root cause of the sludging...That was later re-engineered.

- The 7500 mile oil change interval Toyota specified was found to be optimistic, and Toyota reduced it to 5000.

Toyota claimed that none of the affected engines had been serviced properly, BUT it is not clear if people tried to run them longer than 7500 miles, or if they suddenly decided that 7500 mile intervals were tantamount to improper service.

Bottom line....change your oil according to the 5000 mile schedule or even a little earlier and you almost certainly wont have this problem.

Use a good quality oil. You dont have to use Mobil 1, and I dont even recommend it. Toyota doesnt seem to recommend it in their owners manuals (although they dont knock it specifically)