Mechanics

QUESTION WHAT IS THIS ENGINE RATTLING NOISE

1999 Isuzu Rodeo

Engine Mechanical problem
1999 Isuzu Rodeo Question 6 cyl Four Wheel Drive Automatic 103K miles

Here is what led up to this.
First I needed to change the water pump.
Replaced the water pump and seal

Next I replaced the timing belt and I heard a spring sound go off, so I lost the timing.
Then lined up the markings and heard Backfiring through the intake.I had to do this step about 5-9 times.
I now believe the timing is on now and the backfire stopped, but now I hear rattling sound coming from the passenger lower part of the block. It sounds like a few bolts bouncing around either in the combustion chamber or somewhere in their.I also hear along with the rattling sound, sometimes a knock/slapping sound almost like metal to metal at times.
I realign the markings again and then started the engine up and don't hear any backfire's or slapping metal to metal sound, but the rattling sound is still there. Also when I go to rev the engine the engine bogs and stalls and dies. Now these are my symptons and is there any one out there that can help me. And also along with others who are experiencing the same or similar symptons.
I will also be updating periodically on my progess. Thanks.
Avatar
Knutty1
November 3, 2010.




Check engine compression

Docfixit
Nov 4, 2010.
I will check the compressions today and post them here when i'm done. I hope it turns out okay. Also will carbon build up in the combustion chamber give off the same sound? I will also attempt to steam clean the chambers today too.

Tiny
Knutty1
Nov 4, 2010.
Yes carbon maybe the problem SeaFoam cleans good. That belt is the most difficult one to replace but seems you got it right.
Let me know

Docfixit
Nov 4, 2010.
Well I couldn't do the compression test and steam clean process today. Due to when I let the engine get up to normal operating temps and rev the engine to recommended rpm the engine bogs. And dies. When the engine was idling I went underneath the vehicle and it sounds like the rattling is coming close to the oil pan or some where near it. It feels and hears like the engine is getting flooded when it bogs and dies. No backfiring, just the rattling/knock sound along with CEL light on and flashing. Could this be that my timing is still off? I'm so fustrated right now.I replaced all new plugs, added some engine oil today also and still the same problem.I also witnessed a small amount of smoke coming out between the dirver's side cam and PS pump. Could this side of the engine be the exhaust side or is this the intake side.I don't know. But will update tommorow on my progress. Thanks Docfixit for shining some light for or with me on this problem.I don't want to give up yet.

Tiny
Knutty1
Nov 4, 2010.
Noise did not occure until T-Belt replacement? Is oil dilluted? Contaminated with fuel? The " sprung" sound was taht the cams moving? Any chance something got into engine?

Docfixit
Nov 5, 2010.
Before the t-belt was replaced there were no rattling sound. The vehicle and engine ran fine with no problems. The spring sound occured when I took off one of the idler pulley to take off the t-belt, which if I knew before hand I could of just taken off the tensioner rod, but this was when I heard the spring sound. Put on the belt and started the engine and noticed backfiring issues. DocFixit, the oil didn't smell or look like there's gas mixed w/it. When I checked the dipstick, it was in between the low and high(full) and so I decided to add a little oil to see if that was the problem. One thing I noticed is that my left bank(passenger) side plugs are all wet w/the smell of gasoline. And I don't recall anything dropping into the engine. The only thing was, I replaced the egr valve and while scraping the old gasket off, a very small piece of gasket fell into the tube where the egr sits. I started hearing this sound when I retarded the passenger side cam like a tooth or two, thinking that that would solve the backfiring issue.I hope this help Docfixit. Hopefully I get around to checking the compressions today.I will post them here. Once again thanks for your kindness Docfixit.
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Tiny
Knutty1
Nov 5, 2010.
Well my compression results are as followed today: cylinder #1
50 psi/ 1st try
70 psi 2nd try w/oil added to the cylinder
cylinder #2
195 psi
cylinder #3
145 psi
cylinder #4
195 psi
cylinder #5
60 psi/1st try
110 psi/ 2nd try w/oil added to the cylinder
cylinder #6
195 psi

If there's low compression like #1, #3. What does this mean?

Also started the vehicle and further pin pointed the rattling/chattering noise (almost sounds like something broke in tiny pieces bouncing around in there) where it's more obvious and it is coming from underneath by the tranny oil pan and or the bell shape by the pan. I take it this is the tranny. What could this be?

Tiny
Knutty1
Nov 5, 2010.
Hi, knutty1 I use to own a 1997 isuzu rodeo I bought the vehicle with 150,000 miles on it and since day one of owning it it's always made a tapping and chattering noise these vehicles are natorious for this and it is just your lifters this noise will fade in and out then come back. When I took it to my mechanic after I bought it I freaked out and said what is that noise he told me it was my lifters and to not worry about it that it was more of an annoyance than anything. Well I listened to him and I sold it when it hit 300,000 with it still making that same noise. If you can deal with the noise then it should give u many miles of trouble free worries. Hope this helps : ) p.S. Is it running fine other than the chattering noise?

Tiny
FUNGUY4
Nov 6, 2010.
Also, I would try going with a little thicker oil like 10w 40 I always used 10w40 in mine because 10w30 always made the sound more prominent also would highly reccoment going with Mobil 1 oil

Tiny
FUNGUY4
Nov 6, 2010.
I will try using the thicker oil and see if that helps. Thanks for your reply.I'm going to take off the valve cover on the passenger side and check the valves. With the low compression's, i've heard that wrong valve clearance could have something to do with this, is that true? Also check to see exactly when the valves are opening and closing.I will keep udating to this thread. Some of my friends are thinking that i'm going about fixing this problem in the wrong direction, but who knows. FunGuy4, my vehicle is still sitting because I haven't reinstalled everything back on yet, but will soon be tested after what I mentioned earlier here. Thanks.

Tiny
Knutty1
Nov 6, 2010.

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