Broke timing chain on startup!!!

Sh*t happens!

 

Is the 2.7 an interference engine or non-interference?

 

You'll figure out why it jumped when it's opened up.

My early guess is a failed key on the crank pulley. Totally a guess.

 

Yea we will see....

 

I don’t think it is....

 

Or a failed hydraulic tensioner.

 

Jimmyh - Question if I may? Years ago on some of the vehicles (1974 400ci gm) they had injection plastic formed around the teeth of the steel timing gears. Not much but just enough to quiet the timing chain. When the plastic ages and wears - it might fall off and add much slop to the chain causing a tooth jump (did it on my Monte Carlo).

Do they still do this on engines - and specifically the Toyotas?

 

Good question Canufixit....

Toyota loves putting a Plastic gear in somewhere or other

 

No.. but the chain guides can be plastic

 

They don't do that and haven't for a very long time as that was BIG FLOP on their part. I don't think Toyota ever did it.

I remember back then I was working as an apprentice mechanic in 1971 when they started this and it was bad! We had cars coming in just out of warranty for timing problems and jumped time due to the molded crap on the timing gears. As far as I know GM was the only company to do this ( Pontiac, Chevy, GMC etc... ) The really sad part was even the mfg replacements were all steel with no molding. It's like they knew they were being stupid.

 

Thanks, That's what I thought. Apprentice 1971 ?? You may be older than me ! Old Guys Rule !!!!

 

Me too. I already had a year at the power company under my belt in '71. I don't hang in the 60+ thread 'cause I don't feel old.

@Jimmyh & I do tend to stir our own pot every once in a while though.

 

Don't worry , it won't do it for very long!

 

OK - I've got another question - And I'm hoping for a Definitive answer with Link to sourcing/reference if possible?

I've searched online a lot for this - and do not find a specific answer on line ....

I can find a list of engines with timing "belt" and with / or without "zero clearance" engine info. All info that I can find is for "belts" only. Other info just states that if you have a timing "Chain" it's not an issues do to it's reliability. No site I can find list engines with timing "chains" list if they are ALSO interference engines. I know it is possible to have interference engine with a chain - but where can I check to be certain ???

I post this question here as I have the 2.7 L I4 engine myself with a chain .... and would like to know if this is an interference engine or not .. an it probably applies tpo the OP as well.

Thanks All,
SteveC

 

Don't know for a fact here but generally speaking I've understood that Toyota uses timing chains on interference engines and belts on non-interference. I broke the chain on my 22R-E and it definitely resulted in valve clearance issues. I've know people who's belts broke on 5VZ-FE V6s without issue.

 

Yep!

 

Well nothing else appeared to be wrong.... I always run thick oil “rotella” in everything always have but if I had to guess it was really cold and the oil didn’t ouch the tensioner put like it should have and caused the chain to jump teeth on cold startup? I should have it back today my buddy is doing the work. Wet ahead and put new chain sprockets tensioner water pump and power steering pump bc it had started to wine anyways

 

That Rotella oil, isn't the diesel only oil, is it?

 

Technically but I’ve used it in every vehicle I’ve had lawn mowers dirt bikes 4 wheelers for over 10 years now.... it’s some of the toughest oil made!! Doesn’t break down like junk automotive oil does

 

It's designed for diesel engines yes, but it doesn't hurt anything to run it in a car, it just doesn't have the same friction modifiers and detergents that a typical car oil does.

I run Delo (Chevron's Rotella if you will) in my motorcycle as motorcycle engine oil is needlessly expensive and car oil makes the wet clutch slip due to the efficiency additives.

It's actually not uncommon practice by some to use Rotella every tenth oil change or so to clean the motor up a bit.