1984 300DT 5 cylinder turbo diesel. When I put my ear near the ground in front of the left front tire (driver's side), I can hear a steady rhythmic tick tick tick tick tick tick tick sound coming from the engine.

At first I thought it might be a loose crankshaft bolt on the front of the crankshaft causing the three spacer washers to sing a song. That said, I don't think it is that because the tick tick tick tick is in steady rhythmic time. You could set a metronome or watch to it.

All ideas and input is appreciated!!

Husky, get a mechanic's stethoscope and start probing. See if it changes with engine speed. Some say to use a wood billet of some sort and that will also work but the 'scope is better and cheap enough, about $10.

The major mechanical bit in that area you describe is the vacuum pump.

Thank you for the input. Question, could a bad vacuum pump produce a steady rhythmic tick tick tick tick sound?

I think so. Mine just goes pocka pocka pocka.

The vac pump can definitely tick. If you can isolate it best replace immediately as if it falls apart the parts can jamb your cam chain and stopped cams are a very bad thing for the motor. Pistons hit valves, and valves break cams and or cam towers.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Tonight, I started the car, let it idle down then placed my mechanic's stethoscope directly on the vacuum pump. It sounded normal to me, a "whirring sound" if you will. I did not hear a distinct or stacatto "tick tick tick tick tick" sound.

I then listened carefully to the front of the engine without using my mechanic's stethescope. From up top, I hear a faint tick tick tick tick tick sound coming from somewhere front center of the motor to slightly left of center.

When I listen to the sound from underneath the car, it seems more pronounced than when I am listening standing over the top of the engine. This is puzzling......

Did you listen with the oil filler cap off?

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I'd loosen the injector line nuts one at a time to see if it's a cylinder doing it (ie combustion knock or something related to cylinders)

__________________
1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

Deformed heatshield on DS motor mount?
Loose/failed DS engine shock?
Loose oil cooler bracket?
Loose A/C hose bracket?

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

I'll check all these items as well, thank you for the input. I guess my weekend schedule is filling up.......

Besides the "tick tick tick tick tick" sound I hear when I have my ear near the left front side of the car, on the RIGHT side (passenger), I hear a sound similar to an aluminum coke can filled with gravel. Weird.

This one may be a bearing; alternator is on that side.

The vacuum pump has been mentioned - the cause of many a vacuum pump failure is due to the wear induced on the intermediate shaft bearing.

Remove vacuum pump - push / pull up against the timing device - no noticeable movement should be detectable

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Sounds like I need to perform a thorough inspection of the vacuum pump and front crankshft bolt. I'll take the oil cap off and listen for any unusual sounds as well.

Injector nozzles good? Injectors balanced? Valves adjusted? It might be nailing.

Engine mounts in good shape?

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)