Funny Knocking sound

[graceoverall]

I bought this used 90' MX6 Last December (2005) and during the last three months or so I've noticed this knocking sound coming from the engine which has been getting steadily worse. It happens especially when the engine is cold, but comes and goes. It seems to subside most often when I reach cruising speed. I can't seem to get any mechanic to give me a straight answer, seems like all of whom I've spoken to just want to charge me an arm and leg rather than tell me how to fix it myself. I know it's hard to give advice on this kind of thing without listening yourself. I'll try to post an audio clip in a couple days if I can.

I'm not terribly savvy on the inner workings of an engine and would like to dive in, but I don't have a garage nor the proper gaskets to replace the seals I break. Furthermore, it's my only source of transportation so I can't afford to get in much deeper than a day or two's work if it can be helped.

My poor troubled car. (uhm)

 

[Prodigy]

Double check the motor mounts...

It seems to be a recurring thing when it gets cold out.

 

[otmsp]

Maybe you should change to a heavier or thicker oil.my 2 cent

 

[mx mad]

Do you have the 2.5 V6, if so sounds like the same prob as my 1.8 v6 basically i had the choice of a new engine or a rebore and a few new tappets, basically if you see a lot of smoke pouring out the back every so often especially if you rag it i would be worried.

If the mechanics uhm and aar about it its because it is hard to tell what it is simply because you have to take it apart and look inside e.g costly, my mechanic was the same way and he told me the bombshell whilst i was on holiday in turkey 800 cost me for new engine install.

Im not saying its a defo but just keep an eye on ure oil level and for smoke.

 

[randyscycle]

If there is an internal engine problem, a serious one enough to make noise, any good tech should be able to pinpoint it. If they don't seem interested, there may be two reasons:

1) they don't work for free

2) they are incompetent

An oil pressure guage will eliminate or confirm any bottom end problems. A stethoscope will pinpoint any top end noises, and a experience with engines and repairs in general will go a looooong way. A noise that is worse cold than hot most likely isn't a connecting rod or crankshaft. Oil gets thinner when hot, so the noise there would most likely get worse the hotter the engine.

Pay close attention if there is anything that you can do to make the noise come and go, or make it worse or better. i.e; light acceleration, uphill/downhill driving, cornering, etc.

 

[otmsp]

did i mention heavier oil or maybe one of them oil treatments they really work for high mileage motors.

 

[graceoverall]

Audio Clips of Engine

Hear are a couple of audio clips I took from my engine with my mp3 player. I think the quality is good enough to help understand the sounds it's making. The first clip "Rear Engine" was recorded at the back of the engine just today and you can hear a couple of distinctly different ticking and tapping sounds. The second clip "Front - Rear Engine" was recorded first at the front of the engine and next at the rear. I revved the engine a little on both clips so you can hear that the sounds stay pretty much the same even at higher RPM's but still move in sync with the rotation of the engine.

Sorry, I have to get to class but I'll get back to explain more later.
Thank you.

 

[xelderx]

Mostly sounds like it's in the top end. Try and determine if it's coming from the top of the motor or from the bottom of the motor. It doesn't sound like rod knock , but I recently had rod knock that sounded like higher up in the engine. I though it was a wrist pin going bad. I'm not sure if your motor has solid lifters or not. If they are hydraulic several of them might be stuck. Have ou kept a close check yon your oil level recently? Any abnormal low levels?

 

[graceoverall]

Rod knock? could be...

Well, I'm pretty sure it is on the top end, and it sounds as if it's coming more from the back end near the firewall, right under the fuel injectors. Not sure. I think it's definately something under the valve cover though. Rods, lifters, something. Oil is always full, and I keep oil stabilizer in there too. Thank you.

 

[miss_steele_msp]

that sounds bad.