ritz7

Hey everyone. I have a 1998 Honda Civic Dx with a d16y7. Its bone stock with 227k miles on the clock. The other day it started to have a slight knock but we checked the oil and it was still full. I couldnt find any leaks and the car doesn't smoke at all. Today when we tried to drive it the car was very slugish and wouldn't really move. The oil was just changed around 1000 miles ago with mobil 1 full synthetic 5w-30 and thats what the previous owner was using all along. Now What could the problem be? Is the motor pretty much blown and is in need of a rebuild or replacement? would a fresh oil change help? Thanks in advance everyone.

pityocamptes

Knock as in metallic knocking or knocking on loads, such as a fuel knock?

ritz7

It sounds like metal. I never heard of a fuel knock before. How does that sound?

pityocamptes

Fuel knocking is usually when the vehicle is out of time, normally on loads or acceleration. When you changed your oil did you notice in debris (bearing material) in the oil? If you still have the old filter, can you cut the outer can off and inspect the filter pleats for captured debris?

pityocamptes

Also, what is your oil pressure like? At idle, if you pull plug wires one at a time, does the "knock" go away or is the sound reduced for that particular cylinder? If you do this be careful you don't shock yourself.

pityocamptes

So, is the knocking sound you hear ONLY during acceleration? How about at idle, and slightly revving the engine? Do you still hear it? Any engine light CEL's?

ritz7

I dont have the filter anymore and i didn't notice any debris in the oil. I dont know about oil pressure. How would I check that? I can go try and pull one plug wire at a time and see what happens. Whats the likely hood that the timing belt randomly just jumped a tooth and is now off timing? This all started after my girlfriend drove the car pretty fast due to a medical emergency and I doubt she let the car warm up before taking it to higher RPM's. Could that cause some sort of problem?

ritz7

The knock is through out the whole entire time the car is running. The car has a CEL but its for the cat and its been on for a few months now.

pityocamptes

Does it make the sound at idle or only on accelration? Before you pull the wires, do you have a timing light or can you borrow one that has a rpm readout and timing?

pityocamptes

OK, so where is the knocking sound coming from? Does it sound like its in the exahust? Ten bucks its your cat. When cats go out the car will run like crap and have very little acceleration. I would get that fixed first.

Pieces of the cat may have broken off and that is the rattle noise you are hearing.

I would discontinue driving your car until you get this fixed. You can burn the valves out with the increased back pressure and fuel issues.

dueyx99

in these days of youtube, one could easily post a video of said car knocking

ritz7

Well I just went down stairs and ran the car and the knocking is actually no longer there. It struggled to start almost like it wasnt getting enough fuel or air. It ran pretty rough and sounded like it was a lower rpm. I would compare it to almost a boxer engine.

ritz7

I don't have a camera and my phone doesn't do videos.

ritz7

Also when I pulled the plugs nothing really happened.

pityocamptes

Like I said its more than likely your cat - which can cause your engine to run lean. If you continue to drive it you may burn out the valves. I would replace the cat which will more than likely fix your problem. If you have no emissions laws, I know some get away with pulling it and using a test pipe, but I guess that depends on your local laws...

ritz7

I think I looked under the car before and the cat was welded on. So should I just take it to muffler man and have them weld just a straight pipe?

ritz7

We are in Florida by the way so no emissions.

jbpnoman

Pull the CEL again, and make sure the cat is the only thing throwing a CEL still. Before you go throwing money into it, do a compression and leakdown test, and check your mechanical and ignition timing. If your girlfriend dogged it before it warmed up, that could have caused damage to the motor, and a leakdown test would help you find it. Checking timing may or may not tell us anything, but it's always a good idea to double check when you're working on any car.

ritz7

Ill go ahead and check the light again now. How can I check my timing? Do I need to buy the timing gun they sell at autozone and stuff? What could her getting on it before its warmed up do?

jbpnoman

******* a car before it's warmed up, especially an older car, can spin bearings, blow piston rings, fry ring lands, damage wrist pins...On the plus side, at least it isn't turboed. Then you'd have a whole BUNCH of fun stuff to worry about

Yes, you'll need a timing light. If you can't rent/borrow one, don't waste your money on an expensive one with a bunch of bells and whistles. It's a timing light - it doesn't need to be fancy. A compression tester you should definitely be able to rent/borrow. A leakdown testing kit, maybe not, but that might not be necessary. Let us know what a compression test reads on all 4 cylinders, make sure timing is within spec, and we can actually start to give you a real diagnosis from there.

ritz7

I just checked the codes and its throwing code 4-Crank position sensor and 67- Cat Converter. Would the CKP being bad cause this? What does this mean that that sensor went bad?

jbpnoman

Possibly. Now reset the ECU and see what codes come back. To reset the ECU, just disconnect the positive battery terminal, try to crank the car, and reconnect the terminal.

ritz7

Should I try starting the car after?

ritz7

Well I reset the ecu and now its throwing no codes but it still struggled to start up and when i tapped the gas it kinda didnt want to rev up. it idled with a much deeper tone then usual but there was no knocking sound this time around at all.

pityocamptes

The CKP code is being thrown because of your cars running condition due to the failed Cat. Replace the cat, or get a test pipe and follow the instructions on this site for "tricking" the secondary O2 sensor from triggering - or simply get a new cat and be done with the problem. Resetting the ECU will do nothing. When the ECU cycles again or triggers a fault the CEL will come back on. It will continue to run like crap until you fix the problem, ie - the Cat. The tone change is from your Cat falling apart inside, and exhaust pressure. You will burn the valves out if you continue to run the car with a damaged Cat.