mechanic says bent rod......?

87coupe

New Member
Jul 2, 2009
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michigan
the car would cut out at higher rpms and was told it was fuel cut. then it started cutting out lower and lower till it was down to about 3k. now it wont start. it was'nt that noticable till i took it on a trip to niagra falls and by the time i got home it was done. mechanic told me it's a bent rod. does that make since? i'm kinda new to the supras but i do know a little about motors and it just dont seem right. for it to get worse over a short time then it seems like i would have to bend more and more to point where it's at now... i was'nt ragging on the car and i would think i would need to be for it to bend more and more to the point where it now wont start if thats even possible to bend a rod in that manner. i would have just shut it off but i had to make it home. any suggestions?

thanks
 
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HommerSimpson

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Dec 31, 2007
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New Smyrna Beach Florida
usally a bent rod knocks some.. or if its twisted enough to make the valves hit piston or something in that order.. ask him why he says its a bent rod.. and dont let him touch car anymore... just ask him why ...and let us know...

and id check other things like fuel pressure and spark ...things that are easy to do...and the people on here can help you and walk you threw it step by step
 

rayall01

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Oct 10, 2008
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And saying it won't go above 3000 rpm suggests limp mode. Check your AFM, and the plug for it.An AFM issue will cause it to not rev above 3000 rpm.
 

jdub

Official SM Expert: Motor Oil, Lubricants & Fil
SM Expert
Feb 10, 2006
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Valley of the Sun
Bent rod? Highly unlikely...don't take it to that guy again, he's trying to soak you.

Vs chasing your tail:
1) Check ECU codes
2) Check your timing
3) Check for a boost leak as MDC suggested.

(refer to the TSRM for 1 & 2)

rayall01;1383947 said:
And saying it won't go above 3000 rpm suggests limp mode. Check your AFM, and the plug for it.An AFM issue will cause it to not rev above 3000 rpm.

There is no such thing as "limp mode"...there are however fail-safe modes and back-up mode. Two distinctly different things caused by different sensor/ECU events...fail safe has 9 different sensor failure causes, each with a different ECU response. The AFM is one of them, but not the only one. Back-up is an ECU main microprocessor failure. "Limp mode" implies a single failure...the use of this term needs to die, especially in the Tech sections.

Instead of "guessing" how about checking ECU codes, or is that too difficult a concept to grasp? ;)
 

87coupe

New Member
Jul 2, 2009
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michigan
ok so i was write to think he was off his rocker for saying bent rod. so i'll start digging into it. and see what i come up with.
 

Flateric

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Mar 26, 2008
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Calgary, Alberta, Canada
Ummm, I have had a bent rob before that made the engine break up at higher rpm's which eventually and fairly quickly sent my car into limp mode. It's my theory that it caused a knock sensor to start tripping out alot.

Mine was caused by a BHG, but I had a MHG and it only acted up at very high boost levels at the drags. It got bad enough that eventually I managed to get just enough water in the combustion chamber (it only takes like a thimble full you know) to very slightly bend the rod.

I think I still have it somewhere, I'll take a pic if I come accross it.

I took the head off the block and noticed #3 would not go all the way flush with the block on the upstroke. It stayed ever so slightly low, like 1mm or so each time.

So bent rob is not really impossible. It is however still unlikely but not to be totally written off.