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

Main Navigation

Advertisement
Social Connect
Resources
Our Brand Family
Engine Builder Magazine
Content for engine professionals and enthusiasts
Tech Center

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

Engine Builder
By Engine Builder

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.

Related Articles

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? to 6.465?  (161.3 mm to 164.2 mm). If the length is greater than the maximum, replace the bolt.

 

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

You May Also Like

Engine Components

Choosing the Correct Block for Your LS Engine Build

Whether you’re scouring junkyards, ordering cores, investigating factory options, looking at aftermarket cast iron or aluminum blocks, or spending big bucks on billet LS blocks, you’ve probably noticed it’s been harder to find exactly what you want for the foundation of your LS build than it historically has.

Greg Jones
By Greg Jones

Has it become more difficult?

As we’ve often written about in the pages of Engine Builder, and certainly in recent LS-focused issues, the LS engine family is still a hot commodity. The reasons are many and those reasons are valid. However, as that popularity has remained high from more and more people seeking an LS engine build or doing an LS swap or boosting a junkyard find, the availability of LS blocks are taking a hit. The result has been higher prices in some cases and longer waits in others, leaving people with a more difficult choice.

Read Full Article

More Tech Center Posts
Open Loop/Closed Loop and Learning

Closed-loop control can be programmed to either add or subtract up to a certain percentage of fuel in order for the engine to reach the target air/fuel ratio.

By Andrew Starr
Shop Solutions January 2023

Next time you have set of large journal small block Chevy connecting rods to resize, consider honing the big ends of them for a +.002” outside diameter bearing that the LS engines with fracture cap rods use.

By Shop Solutions – The Power of Knowledge
Shop Solutions December 2022

Everyone misses occasionally, and this helps avoid dents and damage.

By Shop Solutions – The Power of Knowledge
Jesel Certified Performance Rebuilds

Engine components are serious investments for any racer and maintaining that investment could be the difference between winning a championship and losing it.

By Engine Builder

Other Posts

Going the Extra Mile with Cylinder Head Porting

It’s not just the port work alone that creates spectacular cylinder head performance. The most critical areas of a cylinder head are those which pass the most air at the highest speed and for the longest duration. Your bowl area, the valve job, the throat diameter, and combustion chamber are all crucial parts. 

By Greg Jones
Tight Tolerances and Building Power

As you ascend Mt. Everest, you reach an area called the death zone. Once you climb high enough, the margin of error becomes perilously thin. That death zone also applies to engines. As the horsepower per cubic inch and rpm increase, the margin of error decreases. 

By Lake Speed, Jr.
CNC Update: Features and Automation

Precision is key when it comes to automotive parts; the complex designs of connecting rods, pistons and rings, blocks, cylinder heads, and other parts require super tight tolerances that are getting more and more difficult to be met by hand or with other machining processes outside of CNC.

By Evan Laux
All Things Media Blasting

Engine building is a segment of the automotive industry that has always been ahead of the curve in media blasting, and no matter the engine shop, cleaning equipment is a common bond.

By Eric Garbe