High idle & ticking sound on a 300sdl Need some assistance - PeachParts Mercedes-Benz Forum

euroamg · #1 03-08-2015, 09:44 AM

Just picked up a 300sdl from our old neighbour. Need a little assistance on an issue. Ticking sound & high idle on the 300sdl.
You can hear the ticking closer to the middle/4th glow plug area.
Idle is going up down a bit in the range of 900-1100rpm i'm guessing

I linked to my photobucket for the 2 videos.

002D6C11-AC38-4C84-AD9D-0EC5C7E5982E_zpshcnuojot.mp4 Video by c32wagon | Photobucket

27A0C43F-73D6-4315-A122-5C86571EC0DA_zpsxuiy8cbb.mp4 Video by c32wagon | Photobucket

Lucas · #2 03-08-2015, 11:58 AM

Get an auto stethoscope. I would guess injectors. But that's a guess.

sixto · #3 03-08-2015, 03:35 PM

Idle = clean the ELR connector.

Noise = check the injector line clips and separators. Check the belt tensioner damper.

Sixto
MB-less

mytmousemalibu · #4 03-08-2015, 04:28 PM

I don't how many others have had this problem but I had a lifter go bad in the 603 of my 87' 300D. It caused a loud tick that was intermittent and slightly higher idling would induce the noise. The tick eventually became a collapsed lifter and that cylinder would go dead at idle because it bled off all its oil. I replaced all of them and it took care of the problem and actually ran better overall. I suspect the others were getting to be sub-par.

Maxbumpo · #5 03-09-2015, 12:16 PM

I'll second the lifter idea as a likely source of your ticking noise. Personally I've had great luck using M1 synthetic oil. Takes some time, but usually clears up noisy lifters. May take a few tanks of fuel. New lifters are expensive, well worth trying M1 first.

mytmousemalibu · #6 03-10-2015, 07:17 AM

Replacing all of mine cost me about $300 in total. 12 Lifters, valve cover gasket, cross-over pipe gasket, brake cleaner and a tube of Lubriplate assembly grease. I do all y own work so just a bit of my own time but its not hard. Take the chain tensioner out. Zip-tie the chain to the cam sprocket and remove and let sit in the cavity. And then, Just need to evenly loosen & tighten the cam saddle bolts (cam saddles are numbered, take note of direction) a little at a time till they are all the way out and back in. Lift the cam out, pull the old lifter buckets out. With a lint-free towel, wipe the preservative oil off the new lifters, smear assembly lube on the side and top and a dollop on the valve tips and slide the new ones in. Lube the cam lobes & saddles with assembly lube and reinstall everything in reverse and torque to spec. Change oil/filter and run conventional oil for proper break-in.

In my case, nothing was going to "fix" my lifter except a new one. Seafoam would shut it up for a day or two and then it was back.

euroamg · #7 03-11-2015, 10:08 AM

Quote:

Originally Posted by sixto

Idle = clean the ELR connector.

Noise = check the injector line clips and separators. Check the belt tensioner damper.

Sixto
MB-less

I'll check into that if that is the problem..

Maxbumpo · #8 03-11-2015, 03:26 PM

Another possibility: ruptured head gasket at the oil gallery between #1 cylinder and the timing chain cavity. This will reduce oil pressure to the lifters, resulting in a tick...

Another sure sign of the head gasket rupture is an oil gauge the pulsates at idle.