strykersd

Two weeks while on my way back from offroading I hit my first traffic light and notice smoke coming out of my hood, which smelled like coolant. I pull over and all of a sudden my temp gauge goes from it's normal position a little below half way to up past H. I let it cool down for a while, fire the engine back up and notice a small rod knock. I'm almost positive I spun a rod bearing. The symptoms are
-hard to start
-runs fine for 2-3 minutes then it starts knocking and loses almost all power (probably when the oil starting warming up)
-now it's a loud knocking sound
-after it's warm and it dies, it's almost impossible to start.

I've already made my peace with having to get another engine. I'll be picking one up in the morning for $600, but before I put it in I want to make sure I figure this coolant temp sensor problem out. A few weeks ago the car had a CEL from the coolant temp sensor, so I went down to autzone and bought another and installed it. Turns out that didn't solve the problem. Has anyone else had this problem? Is there any wiring fixes for this? Thanks

toytech76

Did you replace the sender or the sensor for the efi? Chances are the code was for the temp sensor for the efi and you replace the sender for the gauge

thook

Did your ECU throw a code 4 or a 22?

If you replaced the right one, you might have a problem with the wiring. I assume the connector looked okay?

strykersd

The connector looked fine, a little wet but fine.
Yeah it was a code 4. I replaced the sensor that was on the front of the intake manifold.

thook

Yep.....that's the one.

Before you go jumping the gun, the knocking you heard may not be a damaged rod bearing, etc. If the ECU loses contact with the coolant sensor, it will run VERY badly and rough....and even knock. So, I'd suggest straightening out the sensor issue before anything else.

You might also drain the oil a bit and look for a copper, metallic tone in the oil. Sure sign of spun bearings and it will be there....that is, if you still have the OEM bearings in your crankcase.

iamsuperbleeder

While we're on this topic about those sensors, why on the 22re's in say a 90-91ish PU or Runner are there 2 sensors on the front of the manifold? What does each do? They've got to be different; I mean, two plugins, 2 different wrench sizes to get them off, 2 different thread sizes, completely different probes; if they do the same thing right there next to each other, why aren't they just tied in together into one sensor; or even, can they be spliced together or are the resistances on them completely different?

Only reason I ask is because my buddy just dropped in a pro-stock motor in his 90 PU and broke the one closest to the head off at the plugin part in the process, and I'm think'n that's what's cause'n the running issue with it... after we fixed the TPS problem, but that's a separate thread...

Sorry, don't mean to hijack the thread; it's still mostly on the same topic

strykersd

It was hard to tell if there was metal in the oil, but that might have been because it's so dark (pure black). With 296,000 miles on it, it probably has a ton of blow by. Plus another thing that makes me believe I spun a rod bearing is that once the engine warms up and stalls, the starter is barely strong enough to turn it over.

thook

As you're facing the motor, the one to the left is the cold start injector switch and the other is the coolant temp sensor for the ECU. The CSI switch doesn't do anything other than control when the cold start injector functions. The coolant temp sensor, on the other, has a much more important role. It plays a part in fuel ratio and timing advance.

Yep....if he broke the coolant sensor, it would run very poorly.

strykersd.....
It does sound like something is wrong if the starter is straining to turn the motor over.

Now, if you need a new motor, why don't just rebuild the one you have?

iamsuperbleeder

oh awsome info man, thanx, I appreciate it!

ok, you can have your thread back now