Hi y'all /problem with 7m

[johnny17]

Hi guys,i'm new to the forum but been messing with toyotas for a while. I just started working on a project car(1974 toyota corolla) that we put a 7m on it but after a couple of runs on the dyno the motor started making a sound like it had bad bearings or a knocking sound(the engine is a new rebuild and all clearances were right) also the oil press is 90psi cold @ 1000rpm and 35 at 700rpm .Having no previuos experience with 7m's before (mainly 3tc and 22r)what should i look for before disassembly of the motor.Any suggestions/past experiences from you guys are greatly appreciated. Thank you.

[86.5 7MGE]

Originally Posted by johnny17

Hi guys,i'm new to the forum but been messing with toyotas for a while. I just started working on a project car(1974 toyota corolla) that we put a 7m on it but after a couple of runs on the dyno the motor started making a sound like it had bad bearings or a knocking sound(the engine is a new rebuild and all clearances were right) also the oil press is 90psi cold @ 1000rpm and 35 at 700rpm .Having no previuos experience with 7m's before (mainly 3tc and 22r)what should i look for before disassembly of the motor.Any suggestions/past experiences from you guys are greatly appreciated. Thank you.

I have heard that the TSRM has the wrong torque specs on the engine in most cases, like for example it says to torque the head down to 58ft/Ibs when in reality it should be around 75-80ft/Ibs. I have heard of some other ppl torquing it to 90ft/Ibs. So it's possible that something might have come loose and that's why you have a knock...Also, you should have 1 knock sensor for a 7MGE, and 2 for the 7MGTE these knock sensors will read engine knock in the cylinders and if one goes off you will get an engine light come on. Have you done any upgrades to the engine? Is it Turbo or NA?

[mirage83]

Originally Posted by 86.5 7MGE

I have heard that the TSRM has the wrong torque specs on the engine in most cases, like for example it says to torque the head down to 58ft/Ibs when in reality it should be around 75-80ft/Ibs. I have heard of some other ppl torquing it to 90ft/Ibs. So it's possible that something might have come loose and that's why you have a knock...Also, you should have 1 knock sensor for a 7MGE, and 2 for the 7MGTE these knock sensors will read engine knock in the cylinders and if one goes off you will get an engine light come on. Have you done any upgrades to the engine? Is it Turbo or NA?

The knock sensors detect combustion-related knock, not the knocking of an engine due to worn or damaged bearing and other mechanical problems. If they read knocking the ecu gets the signal and retards the timing to correct the condition.

OP: Your oil pressures are way out there, much higher than they generally are at those rpms. Could be a bad gauge giving false readings, maybe a bad sending unit. Or the readings could be right and I'm uncertain why they'd be that high. Is your lube system stock?

[johnny17]

Sorry guys it took me a while to come back to this forum (dropped computer and was having it fixed).Anyways we disassebled the engine and found no.4 rod bearing chewed up due to the crankshaft rod journal being cracked lenghtwise,also some of the other rod journals had hairline cracks lenghtwise.Never seen this before.BTW its a turbo engine with stock internals.We have have the same setup on an ae86 corolla running 20psi with stock everything(makes427hp) and had no issues.

Anyways thanks for the help.

P.S. Oiling system is stock we just shim pump for higher pressure.

[Toyota Fan]

I hope you caught that before it was banging around really good I seen what happens when you throw and engine rod it blows a hole in your side wall around 6 inchs wide...