> > >> Some owners would notice coolant loss and leaks on the back side of
> >> the 2.4L engines, resulting in $4000+ of repairs, because head bolts
> >> simply come loose by themselves. I suspect 2007+ engines will suffer
> >> the same fate down the road.
>
> >> "3/6/2008
>
> >> 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 1/2 to 6.465 1/2 (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)."
>
> >>formatting link
> > How did that happen, it seems they were over torqued when being made? >
> According to what I can gather, the threading didn't go all the way to the
> top, and if the bolt starts to loosen at all it pulls out of the head when
> it gets to the position where there aren't any threads to hold it in.- Hide quoted text -
>
> - Show quoted text -
This is something like I would think GM would have done, we has a 82? caddy with the 4.1, everytime we went to the dealer there were 5-6 motors on the floor for the week they replaced under warranty, even my dealer said the 4.1 was probably the worst motor gm ever made. Well maybe the Olds deisel conversion and the Vega were worse but the caddy would blow head gaskets starting at 40000 onward, several I saw on the highway in meltdown mode, black and white smoke out the exhaust. Toy has noted alot of issues with their "becoming #1 in sales but after this much time selling a defect like this it is disturbing.