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
Of the girl, or just the G?! :wink:
Good luck
Haha...:lol: thank you i needed that TMI (too much information).
for the record the G gave me the extra cockiness i needed to land the girl.
i consider myself to be still young but remember the feeling of watching a G-Wagen turn casually into a corner... or ... rumbling by like a herd of horses. yes, the G-Wagen demands attention... :P from the girls too.
*she was the one who walk away as the other girls fluttered to.
Any suggestions about the overheating of the OM603.972 engine?
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......
...there is a product called "Water Wetter" from Redline oil products that reduces the working temperature of the water in a pressurized 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......
Thank you for the suggestion I'll be taking them into serious consideration. beginning with a dual fan system and the Water Wetter.
larger multi-tube... i was beginning some research on radiator tubes in the early 2000s it was a hot topic to change or dress you radiator tubes. i was thinking that there might be a company out there with a G-Wagen application or search them individually. since with all the nylon tech out there,I'm sure there out there.
thanks again
fritzy
Thank you guys for the help so far.
Right now, i have a mechanic (Johnny Benz) working on the G.
My engine over heated due to a y-tube that blew-up while going up hill during rush hour. The rupture was also aided by a partly clogged radiator.
Following fixwin38's suggestions i bought the WaterWetter and plan to use it along with pure distilled water that will be until Mercedes Benz Haiti receives my order of a couple gallons of KFM type 30 coolant and a Citric acid radiator flush. (thank you to all the previous posters on the subject of the 603 engines reliability and overheating).
Today i am having a new Cylinder head installed (along with new HD gaskets and bolt sets), a larger water pump, new temperature sensors and the washed radiator fitted back into the G.
I understand now the problem with the 350GDT engine as it is a bored out 3.0 engine (from 300GD) and a faulty head design from MB and the rad designed (horizontal rather than vertical) has caused this other wise superb G model to be called "unreliable" until 1994 that is.
With the new modifications revised head, larger water pump and KFM type 30 coolant. hopefully these mods will allow the G to run @ proper temperature.
If there is anything else any can recommend or commented i would be gratefully.
Reading through the forums i have new found respect for G owners (In Haiti most of people who own Gs [mostly 270, 400 & 500s] have no passion like you guys). thanks again for your help and information.
Has anyone fitted an intercooler on there G?
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......
Foxwin38 thank you for all the advise it was alot of help diagnosing the problems.
After installing a new Cylinder head installed (along with new HD gaskets and bolt sets), a larger water pump, new temperature sensors the G overheated while parked the fan went off at the right time and everything was operating right and the G sounded about right. except the click...claking of the engine seemed louder (maybe my ears!! :shock: ) the water pressure was normal after about 30 min the temp reached to the 120 into red.
So back to the drawing board: Since Monday I've been having the engine prepared to be pulled out to be re-built. I'm thinking that the piston rings are fried, through Foxwin38 has commented on the bent rod scenario
...bent connecting rods are not unheard of....
Also the exhaust hasn't produced black or even white and the smell was not too pungent. The turbo was not affected by the overheating.
whats left is knowing if the rods have been affected or if it's the piston rings that have fried.
.....these engines do not like synthetic oils...stick to regular grade mineral oil in the engine after the rebuild.......
what oil is recommended after a rebuild? brand? 15w40!?
I'm going to try to upload some pictures from the engine and the car. I'm also posting some of the undercarriage.
Do any of the pictures look unusual?
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 if these are the pics of the actual engine you are trying to repair the extensive rust in the cylinder...
I didn't get to Comment on the photos after uploading the pictures with the pistons showing was the engine after 2 weeks of being open while we were waiting for the head. the rust and oxidation came due the amount of time it took to get the head back. the engine was cleaned and oiled before installing the new head. the pictures make it look worse that it is. [opne engine before and installed head after]photo sequence
...from the pics the engine you have appears to be non repairable...rgds Peter
My options are limited living in Haiti, all the work is being done from my garage at home. when we removed the head there wasn't much we could do to prevent too much air from affecting the metals that were exposed. the last undercarriage pressure wash was done over than 8 mo. ago. so dirt, trash and a messy oil change would explain the crummieness and buildup..
...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
I would be interested in your offers but "private" shipping to Haiti is very difficult right now due to political problems. "oppression of the Bourgeoisie" thank you for the offer.
...if MB made that engine with wet liners then six new liners pistons and rings is the only way to go...
The walls all look and feel smooth and no niks or unusual markings standout/ feel out. The oxidation wiped out quite easily.[with oil and additives]
After installing the new head the engine heatedup to red in about 30 minutes of the test start.
The Rods and pistons are all in good shape and in working condition.
We feel the engine is over heated due to the segments (piston rings/ wet liners).
Not 100% yet on the cause, going to speak with the tech this afternoon.
Pictures date from July 13th through the 19th 2009 and head had been off since June 18th through July 10th 2009. The head took 4 weeks to get, we had to send someone to Miami, Florida for it and travel with it to Haiti.
I'll be posting some more as the work gets done.
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 ....
To add to add about the Dominican Republic they do have some modern facilities but not the expertise, in Haiti we have the experts who do not have the modern precision tools.
The Machine shop I'm using one of 3 family shops in Port-au-Prince, I've personally never been to the actual machine shop but he has done some jobs for us in the past. We've used him to machine and pressure test our industrial and marine generators and he's worked on some of our dump trucks.
fritz
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
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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