AMC Eagle Den Forum

The Shop => Question and Answer => Topic started by: DaemonForce on October 16, 2011, 02:41:52 AM

Title: Annoying grinding noise
Post by: DaemonForce on October 16, 2011, 02:41:52 AM
Not sure where to post this but it seems appropriate here. Every once in a while from a cold start I hear a random grinding noise as if the fan clutch is doing something weird or something up front is throwing the engine out of balance. I still can't tell what it is and here's why...

August: Near the end of my long work season I noticed from a cold start that a slight grinding noise would be audible within the first 30 seconds but it went away after the engine got a little warmer. I had problems with blowback.

September: After numerous telltale signs and leaks were missed, the transmission finally blew up. I rebuilt it and the grinding noise went away. I cleaned up the mildly worn starter quite a bit and cleaned up some other old parts. I did not replace the torque converter and I had to loc-tite one of the bolts because of a stripped hole. I'm hoping this isn't causing me problems already. I plan on replacing the converter when I can swap in my spare engine.

Now: There are no transmission leaks but I am getting a bit of blowback and it somehow makes its way as far as the transmission pan. This is only slightly annoying. The major annoyance is a grinding noise after startup that is a bit louder than before and it seems to shake the car a bit. So far the only way I've managed to correct this is by shutting it off and restarting.

As of late this seems to be killing the car at random stops and it's sometimes difficult to restart. I really don't need my engine failing me this soon and I rebuilt the transmission less than 3 weeks ago. I'm hoping it's something else because I have no patience for either of those things anymore. If it's the transmission going bad again, I'm going to pull a 4SPD from Pick-A-Part and do a manual swap. If it's the engine, I'm going to junk it. Considering all that it's been through lately, it's just too dangerous for me to consider other options. Where should I look first?
Title: Re: Annoying grinding noise
Post by: mudkicker715 on October 16, 2011, 03:18:18 AM
Starter related? Is it loose?
Title: Re: Annoying grinding noise
Post by: DaemonForce on October 16, 2011, 03:39:56 AM
The starter doesn't seem like it could be the cause but it's possible. I've recently experienced a runaway start solenoid and the grinding noise kind of reminds me of that. I tried to wobble the starter but it's in place and I don't see any points where it would be loose. I'll pull it off tomorrow and check it out. I have like 3 spares. Anyway this grinding noise isn't guaranteed to happen every time I start up but it does happen when the car has been sitting for a while. I thought the little gear thingy on a starter motor is supposed to disengage from the flexplate when I take the ignition off of the starting position. Could there really be something wrong with the starter itself? It's been in this car for over 15 years and I'm not really sure how starters fail.
Title: Re: Annoying grinding noise
Post by: Jurjen on October 16, 2011, 05:17:56 AM
Maybe the starter stays engaged after you release the ignition key.

Could  be a welded starter relais, a bad ignition switch or the ignition switch needs some adjustment.
When you hear the noise after starting, you could put it in gear and this will break the power to the starter solenoid (thru the neutral safety switch). If the noise stops, then someting is wrong with the ignition key.
Title: Re: Annoying grinding noise
Post by: DaemonForce on October 16, 2011, 06:37:17 AM
Could  be a welded starter relais, a bad ignition switch or the ignition switch needs some adjustment.
When you hear the noise after starting, you could put it in gear and this will break the power to the starter solenoid (thru the neutral safety switch). If the noise stops, then someting is wrong with the ignition key.
That part sounds very important. This used to be a noise I had to focus on to find. Now it's a loud grinding sound that sometimes happens within a few seconds after start. In other words it starts up fine, a second or three passes and then I hear the grind. That's the part where I panic and shut it off. The starter is clearly not engaging and sticking from the start cycle. I'm going to assume something is engaging the starter after I've already started the car. Oddly enough, I wouldn't be the least bit surprised if the ignition switch is the real culprit. This is going to be painful. >:(
Title: Re: Annoying grinding noise
Post by: Jurjen on October 16, 2011, 07:56:18 AM
I think the ignition switch cost about $3 and is mounted to the side of the steering column.
It is operated by a rod from the ignition key lock.
Title: Re: Annoying grinding noise
Post by: carnuck on October 16, 2011, 08:07:52 AM
Check your converter bolts aren't loose and touching the splash plate! But a dragging starter sounds likely too. Too bad you didn't grab a Grand Wagoneer trans and put it in. 727 is much stronger.
Title: Re: Annoying grinding noise
Post by: GRONK on October 16, 2011, 09:41:35 AM
Maybe you have a critter trapped?

http://youtu.be/5XZMC1M9o04 (http://youtu.be/5XZMC1M9o04)

 ;) Can you describe the noise  ;)
Title: Re: Annoying grinding noise
Post by: DaemonForce on October 18, 2011, 10:07:44 PM
Starter appears normal. It only happens when the engine has been sitting for a while and even then it's only 1/4 tries. I was looking the fan over a bit and it wiggles some. I also noted some fluid leaking around the crankshaft pulley. I believe I found my problem. I'll be replacing my water pump with an older one tomorrow morning. :/