Overheating, Loud spooling, Cooling system, details,
This is my first post forgive its length. thank you for reading and your suggestions.
I came in from college with the hopes of restoring our old 1994 G 350. remembering from 2000-2007 my father was struggling with the truck.
A little history
first a heating problem caused by the original radiator changed which then switch to a plastic replacement (after overheating 6mo. later we purchased a new OEM aluminum radiator), then with a turbo leak we bought a new garret turbo, then the drive shaft after a rough trip to the country side (i.e through Haitian countryside), Transmission problems (also one due to a mistake by a mechanic: he didn't replace the trans fuil filter after opening up the transmission) and lately the over heating problem again.
My father claims that this model is known for the overheating while going uphill and that it was corrected on the later model year. I can't comprehend this since this is a G wagen and knowing what i and other few lucky owners had done in the G-wag (off terrain wise). i can't grasp this knowledge. his explanation came from the Mercedes-Benz dealership in Haiti. (this guy would sell books to a blind man, and make him feel he couldn't live with out them) he even blamed MB, saying that when they changed the head to an aluminum head they handicapped the G.
Since 2007 the 1994 350 G TurboD had been parked and out of service, my father has since bought a 2008 ML 320 CDI which he loves for the take-off and fuel economy. i drove last weekend 465 kilometers on one full tank. 8)
My first week back from college i drove the truck that had been parked for 1yr straight. the G started at first try (pre-cautionary maintenance was done before starting), the G sounded normal but drove heavy (as if i were towing around a small boat or pair of wave runners around town) and sluggish. Also the spooling of the turbo could be heard with-in the truck.
at the time my father only warned me not to go up too many hills and to keep an eye on the gauges. i didn't take the heating problem into consideration since the last problem i knew about was the transmission.
As i was driving to see my girlfriend whom i hadn't seen for weeks since back in country. she lives up the mountain which threw my young eyes is steady elevation between 15-35 degrees up hill and at tight curves up to 45 degrees. 25 min into driving about 25-40k/h uphill my temp gauge was steadily raising. it stayed at about 75 then peaked to 102 and over. due to the traffic and lack of shoulder road i had to crawl uphill for an other 8-10min where i could finally turnoff and see what happened.
I let the truck rest and waited for the gauge to go down. as i was waiting i saw steam pouring out the right fender (as if a tea kettle on high). as i inspected a y-tube near the break lines was busted open. this y-tube connected the water going to the radiator, to something that looked like a water pressure regulator and the engine water reservoir.
I know that the radiator was working well an breathing since i had removed the radiator and flushed it out, i know that the turbo was in full working condition since the months prior to being parked all gaskets were changed and the head cylinder was pressure checked and all that, that is done while replacing the gaskets.
Since i have just started to work and i have asked my father to pass me that car i have been hesitant to invest in the car just yet. currently my mechanics have remove the head tried to get it gauged. it falls that i need to replace the head and a couple other senors.
My questions are:
What is this overheating problem with the G-Wagens?
And what models are affected?
Where can i buy the tubes to replace wall water carrying tubes?
Do the G-Wagens have a special cooling system?
Can i option for a intercooler, in hopes of reducing work and strain on the cooling system? pros and cons
Is it normal to hear the turbo spooling (with the windows up)?
Can any of you explain the kicking when shifting from 2 to 3rd?
i love this G-Wagen has traction and pull to die for. It also got me the girl of my dreams.
**will be post pictures**
Hi the OM603 D 35A engine as fitted to your G' has over the years proved to be a "problem" engine primarily for overheating and the expensive damage that results...MB in their wisdom took the Basic OM603 D 30 engine block and engineered it into a higher performance capability...with not a lot of success when fitted into the G'wagen.....retrofitting the basic non turbo engine into your G' would appear to be the only "longterm" remedy to suit your climate and terrain....the W124 diesel saloon car uses the same basic engine but needs the G' sump pan and oil pump fitted to it to keep the oil circulating to the bearings when driving up steep slopes. two possible causes of the "heavy" feel could be binding brakes from seized callipers/hand brake cables or gearbox problems ......
i love this G-Wagen has traction and pull to die for. It also got me the girl of my dreams.
**will be post pictures**
Of the girl, or just the G?! :wink:
Good luck
Hi I believe that the thinner cylinder walls to accomodate the bigger diameter pistons required to get the extra 50cc combined with the turbo boost causes the problem...there is a product called "Water Wetter" from Redline oil products that reduces the working temperature of the water in a pressurised system..it is used in road rally cars and the like...fitting a wider core multi tube radiator to give a better cooling surface area may help..... or even an independent fan blown radiator plumbed into the water circuit would help the cooling......
Hi Fritz the loud spooling of the turbo could be caused by the failure of the bearings due to the superheated oil when the engine cooked.....these engines do not like synthetic oils...stick to regular grade mineral oil in the engine after the rebuild.....check the inlet manifold interface surfaces for distortion...you do not want to lose your turbo boost to atmosphere....I had a 463 LWB 300gd with an intercooler radiator mounted in front of the existing radiator (no aircon) which helped the high speed cruising temperature.... if water got into the cylinders during the overheating problem measure the clearance of each piston at top dead centre with the surface of the block...bent connecting rods are not unheard of if a piston has "hydraulicked" due to water in the compression cavities......
Hi Fritz if these are the pics of the actual engine you are trying to repair the extensive rust in the cylinder bores are a 100% No!!!! No!!!! they should be honed to a bright shine and checked with an internal micrometer for tolerance, but looking at the pics full screen I do not think you could hone them back to perfection..if MB made that engine with wet liners then six new liners pistons and rings is the only way to go.if it is solid block you might be able to rebore to max tolerance and fit oversize pistons and rings...doubtful because the engine has been machined to a larger bore already....or I can try and locate a "serviceable" 350GD engine and ship it .I have a 300GD Engine and Gearbox from a wrecked LWB 300GD which would get you up and running very economically.without the continued hassle of the 350GD engine overheating..from the pics the engine you have appears to be non repairable...rgds Peter
Hi Fritz Once this particular model engine has been exposed to severe overheating and because the integrity of the cast iron block has been breached by rejigging the volumetric capacity of the piston cavities the block invariably distorts so that the cylinder head does not sit compressed to the block over the entire surface area..this causes the pressurised water system to fail and not pressurise thus allowing the water to boil at a lower temperature...... the Only remedy is a replacement "short motor" .. However...if you can find a Mercedes W124 car with the basic 3 ltr engine OM603 912 it will get you back on the road...a bit slower maybe but where can your drive a 120KM for hours at a time ??
2 problems. The engine is prone to over heating through poor design. this distorts both head and block.The block should be fully reconditioned which will include a reface to match a new cylinder head, the reconditioner should fit this with the appropriate oversize head gasket and along with the other reccomended mods the engine should then be good to go.
The re conditioner will be aware of the second fault and that is , when the cylinders wear, because of the oddity of stroke length over cc the cylinders will wear oval, the block will be rebored and oversize pistons and rings fitted, the slight increase in cc will not be noticed. given that all other cooling components are replaced and or upgraded you should have a engine for life. Good luck.
Hi Bill one would hope that the sort of expertise required to perform this undertaking is now available in Haiti.....there was no precision engineering capability 6 years ago when we had an F8L413FW Deutz air cooled engine needing the block machined to stop oil leaks from the base of the cylinders...damage resulting from a contaminated air cooling duct...and subsequent overheating...
Shipping to Crewe wouldnt be out of the question. But I think there is enough expertise in the Dom Rep.
Hi Bill Dom.Rep. yes! you could be right ...a subject not foremost in the mind when on a 2 week holiday ....
Hi is it possible to strip the engine of all ancillaries and components and send the block cylinder head and turbo for re work/machining in America..."where there are many specialist engine overhaul shops" if you cannot source a standard 300D " OM 603 931 or similar" engine locally which will retrofit with little or no problem...and perform well enough for your environment...
Hi Fritz I think I can speak for all GWOA members in hoping that you suffered no loss of life or property damage during the earthquake...a response would be reassuring to all.... rgds Peter
Thank you for your quick response i know i went overboard on the details.
Fixwin38 Thank you for you input... i was sad to find someone else give reason to an MB G-Wagen flaw...
about the "Heavy" feeling i took you advice and had the wheels and brakes removed and checked [man...the manual labor here is reasonably cheap] i had a rear right caliper grinding on the disc. but not enough. for the feel. i decide to have them pull both the engine and tranny out for a rebuild/on-floor inspection.
By any chance would you/anyone happen to know the reasons that causes the OM603 D 35A to overheat the way it does? [pinpoint if possible-or-where to find a informative article]
Can i option for a intercooler, in hopes of reducing work and strain on the cooling system? pros and cons