Engine Knock sometimes

[joeyzaza]

I was driving home today from work, and my car was running kind of doggy. At first I thought it was a boost leak, so I pulled over.

I got out and checked all the pipes and it all looked good, but I thought I smelled burnt rubber. I started it up and the engine made a loud knock knock sound from the lower section of the engine, then the noise quits. When I give it gas it does it for a second and the noise quits again. I've been reading, but haven't seen any posts where it only knocks sometimes. My timing belt is still on, so I didnt shread that. I had it towed home.

Any insight??? It sounds loud like a rod, definatly not lifter tick.

I would think a rod would knock all the time, not just sometimes.

 

[jking29]

Check your timing belt tensioner. It can make a knocking sound when going out, and can also account for the burning rubber smell.

 

[joeyzaza]

I've been reading non stop for hours and hours. I think my harmonic balancer split, I just put on a new alternator, and we tighten the belt down really good. The car has over 150 xxx miles on it.

I will check the timing belt tensioner as well. Thats what I will spend the next 3 hours reading about. The car is at my dads house, I will be checking it out hopefully tomorrow.

Thanks

 

[DSM4me44]

I just had a knocking noise that lasted form 2k to 3k rpms and went away after. LUCKILY for me I didn't do any major damage because it ended up being my timing belt auto tensioner and the belt was loose.

When I had rod knock in my last engine, you could hear it at idle and it got louder as the rpms went up.

 

[keltalon]

I've been reading non stop for hours and hours. I think my harmonic balancer split, I just put on a new alternator, and we tighten the belt down really good. The car has over 150 xxx miles on it.

I will check the timing belt tensioner as well. Thats what I will spend the next 3 hours reading about. The car is at my dads house, I will be checking it out hopefully tomorrow.

Thanks

How is you oil pressure? Has it changed? I had a rod bearing to fail on me it would knock at startup and when i hold the idle steady at 3000rpm. Make sure there are no metal particles in you oil.

 

[joeyzaza]

When I had rod knock in my last engine, you could hear it at idle and it got louder as the rpms went up.

Its not a steady sound, I would think a rod would keep knocking but it just makes a loud noise and stops, I give it gas and it does it and then stops. I'll update it when I go check it out.

How is you oil pressure?

I am using the stock oil pressure gauge. I was cruising on the highway, and it was in the middle. I'm going to cut open the filter on Monday, and prey for no metal shavings.

Thanks guys, wish me luck

 

[nuclearr]

I would check the harmonic balancer first. Then check the timing belt tensioner and idler pulleys as well as the hydraulic tensioner. From my experience you can tell if the hydraulic tensioner is bad by taking off the upper timing belt cover start it up and see if the belt gets and slack between the cam shafts while running. Also check the belt for unusual wear (like melting) that would be signs of the pulleys (tensioner and/or idler) locking up due to bad bearings.

 

[joeyzaza]

From my experience you can tell if the hydraulic tensioner is bad by taking off the upper timing belt cover start it up and see if the belt gets and slack between the cam shafts while running.

I took off the cover but did not start the car. I looked at the timing belt, and in between the cam gears, I pushed on the timing belt. It went down a good half inch or so. I'm stopping by it today to check that.

 

[joeyzaza]

Well I'm at my dads checking out the car. Here are the results, if I take of spark plug 1, the engine no longer knocks. Otherwise it does when taking off all the others.

So next I take off the pan and inspect. This is going to be my engine build thread.

 

[95GSXCO]

So a rod bearing? Dam that sucks mines doing it to never thought about just pulling a plug wire off! Maybe I will get luckly and just be my timming ten. because I can see the belt jump a little around 3000 rpm when the knock starts.

Good luck post some pics up!

 

[95Eclipse]

Well I'm at my dads checking out the car. Here are the results, if I take of spark plug 1, the engine no longer knocks. Otherwise it does when taking off all the others.

So next I take off the pan and inspect. This is going to be my engine build thread.

Piston Slap?
I've been reading about this because my car has been knocking and whining, more when cold and.. only at 3k rpm and higher when at operating temps. and piston slap should also be taken into consideration.. you gave one of the symptoms here..
They say that if you take the spark plug out of the piston you suspect is "slapping" and the noise stops you clould have piston slap. I just thought I throw my 2 cents...
I imagine also any thing else that could be loose in in that cylinder like the rod or piston pin could make a mild knock..

(disregard this if this isn't hapening when you first start the car, since piston slap is mostly present when cold because the piston expands at higher temps so the noise goes away..) another symptom for piston slap is excesive oil consumption .. you might wan to look into that..
Good Luck!

 

[joeyzaza]

Good luck post some pics up!

Thanks, I will be taking plenty of pictures. I will be pulling the oil pan off on Monday.

My eyes hurt from reading!! I'm going to rebuild the bottem end, and then get some work done on the head. I'm starting to look at what rods, pistons and bearings I should get.

I will be pulling the oil pan off on Monday. I'll post some pics of my findings.

 

[joeyzaza]

pulled the exhaust, transfer case, and finally the oil pan today. I found bronze color metal shavings in the bottom of the pan. i reached up to the rod from cylinder one, and it moved back and forth.

I am thinking of buying a jdm 7 bolt and dropping it in for a year, while I slowly build my other engine. Money is tight, and its my daily driver.

thanks for all your help.

 

[Red97Eclipseboy]

Man, that sucks. Good luck.

 

[keltalon]

pulled the exhaust, transfer case, and finally the oil pan today. I found bronze color metal shavings in the bottom of the pan. i reached up to the rod from cylinder one, and it moved back and forth.

I am thinking of buying a jdm 7 bolt and dropping it in for a year, while I slowly build my other engine. Money is tight, and its my daily driver.

thanks for all your help.

Post number 5. Since my engine failure I have only used king engine bearings


King Engine Bearings, Inc.