Hilux 4x4 Forum

Good day

I have a '93 Hilux with a 7M-GE motor coupled to the existing 4Y Toyota gearbox. The engine is excellent with the last measured fuel consumption near 10km/l.
Unfortunately the excellence stopped this Sunday when I drove back to Bloemfontein from Lichtenburg. The engine ran well until about 10km before Bloem when a strange sound came from the engine. Afraid to damage anything further I switched it off and got a friend to tow me the rest of the way. I have no idea what it could be as the bakkie still had power. I have a video of the engine running but can't seem to upload it to this post. It sounds as if something is loose inside the engine and knocking irregularly when the engine is running. As I said, the bakkie drove fine the whole way until suddenly it didn't anymore. If anyone can help with a diagnosis it will be much appreciated. I can send the video as well if anyone has an idea or if someone maybe knows about someone in the Bloemfontein area which can help.
Thanks in advance.

Regards

Welcome Enno.

It's nearly impossible to diagnose like this .... could be a number of possibilities. Physically being there and hearing the sound and where it's coming from (top or bottom of the motor) would help, but even that is no guarantee. It's an old motor so if the sound is low down I would hazard a guess and say that you've possibly run a crank or big-end bearing. If it's in the front it could be that the timing chain / chain guide / tensioner are buggered. If it's at the top it could be that there's a camshaft or cam follower problem.

Only way is to strip the motor. Then rebuild it if the bores are still good and not too badly worn.

Here is an excerpt from a site called, "7M-GTE: Everything you need to know.

KNOWN PROBLEMS

"Quite a few Toyota engines of the past have been known for excessive oil consumption. This problem occurs from worn down piston rings is common on the 2AZ-FE and other Toyota engines. Luckily, the 7M-GTE doesn’t have an oil consumption issue, but it does have an issue with blowing up.

During the assembly, Toyota failed to torque the head bolt as tight as they should have been. Once this issue was discovered Toyota changed their assembly process and raised the torque spec for the head bolts. Because of this issue, a massive majority of 7M-GTEs experience a blown head gasket at some point. If the engine is old, it can experience many blown head gaskets throughout its lifetime. The simplest way to fix this issue is to simply re-torque the head bolts to the proper spec, but sometimes the problem is worse than that.

Another common issue with the 7M-GTE is rod knock. Unfortunately, Toyota didn’t build the 7M-GTE to extremely high standards like they did with the 1JZ. If the rod knock issues persists, you may end up with a blown bottom end. Basically, the 7M-GTE was one of the least reliable Toyota engines produced in the 80s and 90s."

Here is a link to the whole site: https://dustrunnersauto.com/7mgte/

Shutting it down when the noise started was smart thinking.

- JAMES

Thanks for the input so far, it is much appreciated! There is a mechanic here that suggested that I bring him the vehicle so that he could take a look at it, but due to bad past experience, I don't want to just take the vehicle to the first available mechanic. That said, is there a reliable mechanic that someone can refer me to? The mechanic I spoke to suggested it would be cheaper to just buy another 7M engine instead of rebuilding this one. I've read on this forum that it is anyway preferred to rebuild the engine when it is bought? I think it was Mark (Gunta) that sounded like an expert on these engines that suggested it. So maybe if someone has a reliable source that will be able to do the rebuild?

Regards

Welkom Enno,

Gunta lives in Moz now but yes, he know them pretty well.

If they are still around, an oldish guy from President Motors was know for his knowledge?

Or if you could get it to Welkom, oom Pontie ken al die ou enjins agterstevoor!