OK, I’ve got a 1987 Ranger 2.3L/Automatic, which I’ve restored from the ground up. During the 1-1/2 years I’ve owned it, I’ve posted several questions on these forums, of which many were very helpful. Unfortunately, I still have one ongoing issue that irritates me, and I’m going to be very descriptive here to hopefully give enough information to be of value to any potential member that may offer suggestions or solutions. Here goes:

1st, let me say that I’ve replaced just about each and every component imaginable, and I’ll try to list most of them.

1> ECU (Computer brain)
2> EGR Valve
3> ALL relays
4> ALL sensors
5> NEW distributor
6> NEW fuel injectors
7> NEW fuel rail
8> NEW fuel pressure regulator
9> NEW vacuum hoses, as well as all others + belts
10>NEW water pump
11>NEW timing belt
12>NEW oil pan
13>NEW oil pump w/pickup & screen
14>NEW seals
15>Rebuilt trans & torque converter
16>Balanced driveshaft
17>New shocks
18>New bushings/front end parts
19>New alternator
20>New heater core
21>New spark plugs, wires, caps, all ignition parts
22>New TFI module
23>New electric fan
24>New power brake booster
25>New Oxygen sensor
25>New carpets, door panels, dash pad, floor mats, seats, paint, bed cover, etc.

Lot’s more, but you get the idea.

Anyway, the one most annoying problem that comes and goes is a knock or rap on the lower right side of the motor (passenger side, sitting in the cab). By the way, the truck had been left with my mechanic for 2 weeks while I was on vacation a few months back, and he drove it daily, with his high end test equipment sitting on the seat, floor, hooked up like a NASA shuttle. I must say too that it has never been so perfect, runs like the day it was off the showroom floor. But that damn knock. It seems to be temperature related. When cold, absolutely nothing. After the thermostat opens up, come to a stop, take off, knock, knock, knock, speed and load related, yet it quickly disappears within seconds. The hotter it gets, the louder it is. If I stop the truck, go into 7-11 for 5 minutes, come out, start it up, no knock. Drive it for 2-4 minutes; come to a stop, knocking again. My mechanic verified when he changes the oil pump that the bearings and caps were OK, and I do have oil pressure.

I’m wondering, from reading around if it could be:

Spark knock
Octane knock (I’ve tried regular to ultra, no difference) (what’s this octane rod??)
Timing related issue
Something in the tranny?
Incorrect spark plugs or gap (O.E.M./Stock/factory gap)

I’ve tried 10W40, 20W50, straight 30W, 50W, (oil) all make no difference.
I’ve tried different oil filter brands, no difference.
I’ve changed the oil every 1,000 to 3,000 miles, no difference.

Other than the knock, I love the truck, it’s close to perfect.

Does anybody have any ideas or possibly a top notch Guru who could diagnose?

(Dealer, as far as I’m concerned, at least here in NJ, have a bunch of incompetent kids, albeit they may be learned in the NEWER vehicles, etc., this is a 15 year old technology that needs a crackerjack to diagnose and repair.)


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OK I'll bite. Does it knock all the time after it starts knocking until you go into the 7-11? Or does it knock on acceleration, speed and load as noted? I am unclear. If it comes and goes, and is related to load & speed, after warmup, it would be a different problem than a continuous knock after warmup. Please clarify.
Also: Does it sound mechanical, like parts banging against one another or cam/valve/lifter noise? Or spark knock/pre-ignition. Can you make the noise come at will by doing something particular, like going to the store, and turning right coming out of the parking lot?

tom

 

Absolutely nothing to do with 'moving', as in driving. Noise can be duplicated, AFTER WARMUP, by holding brake down, slightly giving gas to say, 1200RPM, and knock occurs. Occurs at passenger side, low. When cold, noise is not apparent. Oil pressure is good/high, at all times. (As I said, I replaced pump & pickup, just to be sure it wan't oil pressure related.)

Also, it is getting worse daily. My mechanic says to drive until it dies. I'd prefer to replace block/head with a GOOD rebuilt or new, and forget the knots in my stomach....as it's annoying.

Noise seems to go away once higher rpm's are achieved, only happens when warmed up, and at low speeds, usually when starting from a dead stop.

Bob

 

Have you checked that all engine accessories are bolted tight, like p/s pump, alt brackets, etc? I've had a p/s bolt break and the bracket rattled like a rod knock on my 2.3. Have you checked motor mounts? Torque converter/flexplate bolts tight? Starter tight?

 

Didja check the converter to flex-plate nuts & bolts. They can allow the TC to flop around as the rpms change. I have a used-up exhaust system that has a loose & rattly sound at 3000 rpms. Now that it is getting worse, it has the same, but quieter, sound a 1500.... My noise is (I think, am to lazy to crawl under) part of the heat shield on the exhaust pipe. I need a BIG hose clamp, or two of them attached end to tail to go around whatever is loose. AND, the noise is just about a the feets of the passenger side... where the exhaust stuff is located... MEbbe you should 'go play in the dirt again' and see if the exhaust has a fitment problem.
tom

 

I've got the same engine knock on my '89 4 cylinder. (8 spark plugs). Drives me crazy too!
I just found this fix and will try it when I get a chance:
http://www.generation-edge.com/forum...?TOPIC_ID=4905

 

My mechanic told me three years ago that it's carbon buildup and to add Marvel Mystery Oil (MMO) into the gas. It should remove the carbon. What he didn’t tell me is that I need to make the truck almost redline while under strain. Well for a while I added the MMO but to no avail. I just used high-test gas and lived with the knock. If I used 87 octane it was unbearable.

Last night I stopped at the Mobil station and waved my speed pass wand and then realized that they were out of the premium and only had 87. So I filled up anyway. I drove away knocking & pinging.

That night I came upon this website and this one: http://www.generation-edge.com/foru...p?TOPIC_ID=4905

I NEVER rev my engine past 2.5. I'm just a mellow driver in my truck. My other car is a DeLorean -- then I can cut loose! Anyway I took the web site's advice except instead of using the carb cleaner as instructed I put the MMO into the gas and simply beat the snot out of the truck up every hill I got to on my 53 mile trek to work. It knocked like hell at 4K but to my surprise after the third or fourth hill the knock WENT AWAY. EVEN WITH 87 OCTAIN. I then drove home all mellow like and NO KNOCK. I CAN"T BELIEVE IT!!!

So add the MMO put some weight in the back and scream the sucker up some hills and the carbon will burn out. it seems to have worked for me. Just revving it up isn’t going to do it it needs to work hard up hills in third gear (it’s a standard) with weight in the back. I have 10 40lb bags over the rear axle for winter traction. It’s only two-wheel drive.