OK - this really has me confused; I hope someone can be of help...

[Trevor C.]

OK - this really has me confused; I hope someone can be of help. I’ve attached a video of my ’97 3.4that’s running really bad. I have:

• Loud ticking sound from what seems like an area behind the fan and pulley area (used a mechanics stethoscope to try to isolate the area where the ticking was coming from)
• No power – won’t even keep up with traffic

Here’s what I’ve discovered:

• Vacuum test is normal – steady reading with engine vacuum within normal range
• No white vapor from exhaust
• Gauge shows normal operating temperature
• Idling rough and at a low (700) RPM
• Exhaust blows strong. Does not seem to be plugged in any way
• For some reason, the windows started fogging up at around the same time (not sure if there is any relation to the other issues)
• Timing belt and water pump replaced about 20K miles ago
• Engine has 190K miles

I’m going to pull the timing belt cover off this weekend and start to figure out what’s going on, but was really interested in your thoughts. Can you help?

Thanks! Here’s the YouTube link. (I hope it works – never done it before):

 

[Skidmarcx]

Maybe pull the timing cover to verify the engine is in sync... Bad tensioner?

Just read that you're going to do that... You could pull the plugs for inspection too

 

[nor_cal51501]

I can't rely hear it that well from your video, but it sounds like a rod knock….

 

[Trevor C.]

Thanks guys! I hope it's a tensioner instead of a rod! Would a tensioner go bad quickly? This came on fast.

 

[RS Dude]

Maybe a loose valve...when was the last time you checked valve clearances?

 

[BrianSD_42]

There are no codes?

Really?

 

[TheDurk]

Verify that your crank pulley/harmonic balancer is not bouncing around. 20k after a TB change, I have bad visions of an under-torqued crank bolt leading to a slipping crank pulley. Bad things can happen quickly if this is the case so it needs to be ruled out ASAP. Your engine's survival may depend on it.

That bolt needs to be torqued to 217 ft.-lbs. More than one shop has half-assed it.

 

[LittleCaesar]

As Durk said, check the crank bolt torque spec

Perform a compression test. See what the numbers give ya.

Loosing any coolant?

 

[Trevor C.]

Hi thanks for the reply. That's inititally what I thought it was. However, wouldn't I get a variance on my vacuum reading if my valve's were loose? Also the knock seems to be coming from the front of the motor, not by the valave covers.

Thanks for the feedback

 

[Trevor C.]

Great stuff. Thanks guys. Yes, I have lost some coolant. I'll be sure to get on this ASAP. I don't want to cause any more engine issues.

Thanks again

 

[Trevor C.]

Nothing shows up. I'll check again..

 

[Trevor C.]

OK - the saga continues. Yes, it was just like TheDurk said; under-torqued crank bolt leading to a slipping crank pulley. It cracked the crank pulley. Timing was way out.

I haven't driven it to keep it from being damaged, but when I went to start it to move into the garage it wouldn't start.

Got crank pulley issue sorted out, lined everything up - it all stayed in place nicely when I checked it (3 complete revolutions). Compression felt strong when hand turning - no binding. Put it all back together.

It still won't start. No strange noises. Turned it over and checked for codes (none show), Reset computer. Checked fuel and spark. All good.

I'm at a loss. Any thoughts? I could really use some advise at this point Thanks in advance.

 

[kball]

Did you redo the timing belt or a mechanic? Are you sure it's timed right? Sensors plugged back in like the cam sensor behind the top cover?

 

[TheDurk]

Did you pull the sprocket and check the keyway? If the pulley cracked, there is a good chance the key is sheared, so you may be lining up the sprocket/pulley but the sprocket is not lined up with crank itself, leaving you out of time.

I think you should break it down and reinstall a new timing belt. Check the sprocket and keyway for damage.

 

[Trevor C.]

Hi kball. I redid the timing belt with a friend who is a professional mechanic. We marked all the timing marks and everything lined up after we did 3 complete revolutions via hand turning of the crank. The only sensor that I remember unplugging is the one that is clipped on the front of the top cover. I'll recheck it. Is there another sensor that is normally unplugged during this process?

 

[Trevor C.]

Hi TheDurk. Yep, the sprocket/pulley was damaged. I replaced the sprocket/pulley and the keyway. Fit on nicely. No movement.

 

[Trevor C.]

I also torqued the crank bolt to 181 lbs.

 

[kball]

Hi kball. I redid the timing belt with a friend who is a professional mechanic. We marked all the timing marks and everything lined up after we did 3 complete revolutions via hand turning of the crank. The only sensor that I remember unplugging is the one that is clipped on the front of the top cover. I'll recheck it. Is there another sensor that is normally unplugged during this process?

That's the cam sensor. Normally that's the only sensor you will disconnect except for maybe the maf if you take the air intake off.

Sounds like you got it all buttoned up right... don't know why it won't start.

 

[Trevor C.]

Yeah, me neither! I'm thinking maybe a vacuum leak or perhaps the cam sensor is not properly connected - would that keep it from starting? I didn't take off the air intake.

I'll go look at it some more this afternoon..

 

[TheDurk]

Yeah, me neither! I'm thinking maybe a vacuum leak or perhaps the cam sensor is not properly connected - would that keep it from starting? I didn't take off the air intake.

I'll go look at it some more this afternoon..

Yes, leaving that sensor disconnected will keep it from starting.

Did you mess with any engine grounds? Like the one by the diagnostic connector ...or the one from battery to fender?

See if you have spark, just pull a plug wire wire, stick a drill in it, and hold the end near the block while someone cranks. Use an insulated tool or insulated glove to hold the wire. (FSM approved technique.)

Then pull a plug or two. They should be a little wet with gas by this point if you are getting fuel. If they look dry, spray some starting fluid in the intake and see if it catches.