Loud buzzing noise, knocking idle, boiling PS fluid?

bunpoh · **Joined:** Tue May 12, 2020 2:52 am **Posts:** 14

Yesterday my partner was running an errand while I was doing aesthetic work on a motorhome we are hoping to have up and running soon. He said the engine started running rough and the lightning bolt dash light came on. Hit the accelerator and it smoothed out. He pulled into a parking lot and turned it off. Tried to start it, no crank. Tried the throttle reset, then the 30 second electrical reset, no love for either. Tried to get a jump off a Cummins truck, just clicked. Wiggled wires to alternator, lightning bolt went off. Tow truck driver couldn't get it started off a little box, but when she jumped it off her giant rig, it started, battery was charging off the alternator. She said it might be the alternator going out, though we did an emergency replacement from O'Reilly's about 2 years ago (same thing, lightning bolt dash light, running rough, pulled into parking lot, no start, no crank, dead battery, alternator tested bad.)

Ran it to where we're staying, a few minutes away, drove fine. Figured we'd just unbolt the alternator, take it to O'Reilly's, get it tested, replace if necessary.

BUT...left it in the driveway running to idle for 15 minutes to charge battery...came back to turn it off...engine running with loud rhythmic thumping noise, like it was maybe missing at idle, with a LOUD buzzing noise from the side of engine somewhere near the power steering reservoir, which was bubbling! Never heard anything like it before. Worried to start engine again.

This constellation of symptoms confused the heck out of me. Ideas?

FYI: Other recent issues...brake light came on briefly after hard braking, went out after restart. Partner had banged up undercarriage (only stock skid plate) trying to park on massively chewed up pavement/ditch area, was a little worried something got mangled, but no further issues with that for a while. Occasional rough engine/missing after starting...turn off, wait, turn back on, goes away. Overheating only while climbing hills on hot days (staying in Arizona trying to fix up this motorhome), recently overheated and partner panicked and shut down forgetting cool down, boiled over a little, but has driven fine since for several many hundreds of miles (probably at least 600.) Was about to do the Hayden 2905/gasser fan replacement. 215k on engine. ORM mod only. Needs timing belt done.

bunpoh · **Joined:** Tue May 12, 2020 2:52 am **Posts:** 14

Update: we decided to start her up this afternoon and see how she was running. Started fine, ran her for 15 minutes, no weird noises, engine dieseling normally, power steering fluid and pump looking, sounding and working fine when wheels turned. Turned off and restarted, no problem.

Decided to take her up to our mechanic's shop to park out front of his garage (with his permission) in case of further no start issues while we remove the alternator and walk it over to O'Reilly's a few blocks away to have it tested. And I can work more on my motorhome prep. Partner removing alternator now.

Still open to any thoughts and suggestions.

geordi · **Posted:** Mon May 30, 2022 9:15 pm

Based on the description, what I see is that the alternator is probably not charging - these have a clutched pulley design and if that is not functioning OR was never there in the beginning, then the battery is not charging properly and WILL be drained down until the computer's math starts making 2+2=32 or equally improbable results. When that happens, the computer can register any number of codes (which should be cleared and ignored for the moment) and engine operation becomes very problematic.

I would start with charging the battery OUTSIDE THE ENGINE (NOT hooked up!) for at least 10 hours, most chargers are going to take that long to get the battery back to full status if it has been pulled to near-zero. You don't want it connected to the computers so that the higher voltage doesn't damage anything. Next, if this has a lifetime warranty, swap out the alternator. It's just a better idea b/c this likely is the culprit right now.

After that.... Clear any codes, try operating it, and go from there.

To answer your email - Here's some basic info that might help you get the most from your CRD and know what it might need:

I'm the traveling CRD tech, people pay me to go around the country and work on these specifically b/c they are such a unique engine. The CRD IS a reliable platform once the (relatively few) design flaws on the engine are resolved, after that it is just regular "Jeep stuff" and things that every car needs.

If you find one that has already had my Level 3 service done to it, the engine will be reliable for at least the next 200k miles. The issues and their approximate miles however, are:

100k miles or 6 years: The timing belt and water pump needs to be changed. If this cannot be PROVEN with either a sticker or receipt for parts / labor... Then it has not been done. MANY people sell or trade the vehicle rather than pay for this service, which is why it must be PROVEN to be trusted that it has been done. Not doing it risks the rocker arms (designed failure point) and that raises the repair cost. Unlike a VW, the head is not damaged when the timing jumps or the belt breaks. This is my "Level 1" service.

130k-150k: Factory head bolts weaken and allow a head gasket leak to develop. The first indication of this issue is frequent "low coolant" alarms. ARP studs are a cure, but must be installed BEFORE the leak presents itself. A simple test can show whether the leak is happening. This is my "Level 2" service and includes level 1.

~200k, but could be anywhere from 150k and above (more common above 200k) is exhaust valve failure. This WILL result in severe engine damage and CANNOT be accurately predicted. There is no warning for when this will happen. The valves reach a fatigue wear point around 300 billion cycles and the alloy in the stem fractures in an instant, dropping the valve into the cylinder. The head and piston are destroyed and MAY jam the piston sideways in the sleeve. IF the piston and sleeve are not jammed, the engine IS rebuildable. But it is much better to prevent rather than let this happen. This is my "Level 3" service and includes everything from 1 and 2 and a lot more.

bunpoh · **Joined:** Tue May 12, 2020 2:52 am **Posts:** 14

Thanks, Geordi!

Update - we do have a bad alternator clutch, after bench test at AutoZone. We are getting warranty replacement, comes in today.

Having a vacuum solenoid issue as well. The big solenoid was what was buzzing. Got code P1140:

P1140-VACUUM RESERVOIR SOLENOID CIRCUIT SHORT TO GROUND .
P1140-VACUUM RESERVOIR SOLENOID OPEN CIRCUIT .
P1140-VACUUM RESERVOIR SOLENOID SHORT CIRCUIT .

Partner picked up the bigger vacuum solenoid, turned it over to check wiring, stopped making noise but now no AC in the cab, in Arizona, lol. Not sure if it's a bad or loose wiring connection or bad ground or blown fuse. Will be checking. Also worry about that crazy wiring harness issue.

Can't get a new solenoid of either type right away. They have them at a place called AZMopar in Peoria, which appears to be online only, but has an address and phone number. If one of the solenoids is bad, we could rent a car and go pick one up, I'd think. Three hours round trip, but otherwise we'd be waiting til the 8th or something.

bunpoh · **Joined:** Tue May 12, 2020 2:52 am **Posts:** 14

About the buzzing vacuum solenoid...asked partner to write up what happened next:

"Yesterday, the Vacuum Modulator Valve(VMV) was what was buzzing. I removed it from it's bracket and flipped it over to check it's electrical connection. When I replaced it, it quit buzzing and the A/C quit working.

Today, with the engine off, I tapped the bottom of it firmly on it's bracket(The purple arrow), than replaced it, and started the engine.

The A/C started working once more, with a vent temperature of 55°F on full cold & fan on high. Oddly, the engine seems to be running smoother than before!?!?"

So, yay! We didn't find any evidence of bad wires or hoses. Geordi pointed us in the direction of the vacuum system diagram...involves turbo, brakes and AC. Hmmm...engine running rough intermittently, brief brake warning light, AC goes out but comes back on with messed with. :BINGO:

I think we have a candidate! Will go ahead and replace the solenoid when we're going to be in one place long enough to order it!

And the alternator was warrantied by AutoZone, so partner replaced it today! Running great! Big thanks to Geordi and all the people on Lostjeeps who left precious helpful threads on these topics! :BANANA:

bugnout · **Posted:** Thu Jun 02, 2022 4:08 pm

Boiling PS fluid very likely wrong fluid. The KJ's PS takes transmission fluid not PS fluid. I made the same mistake a long time ago.

Billybob · **Posted:** Fri Jun 03, 2022 2:45 am

There was Technical Tip issued for the 2002/3 to have their KJs Power Steering fluids drained, flushed and filled with ATF +4.

I personally had no confidence in the local Jeep Dealers here in South Africa to do this and continued using the Mopar Power Supply fluid with no issues at all for the last 20 years in my 2002 2.5 CRD.

There must have been a reason though for that warning to be issued so I can believe that some people have issues with the PS fluid! :wink:

Loud buzzing noise, knocking idle, boiling PS fluid?

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