OM 602 290 GDT Radiator cap pressure rating

Gwagon7

Member
Joined
Oct 9, 2008
Messages
70
Age
55
Location
Cape Town
Hi all I am having some cooling issues with my G and we have narrowed it down to perhaps the wrong pressure threshold on the radiator cap. Currently there is a 0.9 bar or 13 psi cap and I cannot find any literature anywhere that gives the correct rating. I have anecdotal advice to say it should be 1.1 bar or 16psi. Any help much appreciated especially from those with a 290
 

Doug Nel

G-Wagen Club SA
Joined
Oct 11, 2008
Messages
554
Location
Cape Town
Hi Peter. Looks like the cap should be 140. Hopefully there is not something else wrong
1619504819073.png
 

Gwagon7

Member
Joined
Oct 9, 2008
Messages
70
Age
55
Location
Cape Town
Thanks Doug - may be the viscous - although I replaced it less than a year ago. These 290's are great when all is good but they are very fragile when it comes to heat!
 

Antony

G-Wagen Club SA
Joined
Nov 17, 2008
Messages
939
Location
Johannesburg
Hi,

The 290s are awesome but the overall design doesn’t play well in our warmer climate.

There had been quite a lot written on the forum about the heat issues on the 290. Do a member search on Waldi and you’ll see detailed posts on his experience and solution.

Most of us that own them have added a transmission oil cooler into the mix to help a bit.

Something to note though, according to Dirk Wentzel, a Merc mechanic with extensive experience on Gs in general is that the specced operating temp for the 290 GDT is 105 deg C and running higher is within spec when climbing or towing but should not be for more than 10% of the time. I find if the cooling system is working properly, the gauge goes up quickly but comes down quickly too once you reduce boost.

Regards
Antony


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Gwagon7

Member
Joined
Oct 9, 2008
Messages
70
Age
55
Location
Cape Town
Hi,

The 290s are awesome but the overall design doesn’t play well in our warmer climate.

There had been quite a lot written on the forum about the heat issues on the 290. Do a member search on Waldi and you’ll see detailed posts on his experience and solution.

Most of us that own them have added a transmission oil cooler into the mix to help a bit.

Something to note though, according to Dirk Wentzel, a Merc mechanic with extensive experience on Gs in general is that the specced operating temp for the 290 GDT is 105 deg C and running higher is within spec when climbing or towing but should not be for more than 10% of the time. I find if the cooling system is working properly, the gauge goes up quickly but comes down quickly too once you reduce boost.

Regards
Antony


Sent from my iPhone using Tapatalk
Thanks Antony - I actually own Waldi's G and have for some years now so I am well versed in the issues with them. I can certainly add to the overheating discussion as I have spent some time remedying it. I think we are in a good place now - I was unsure of the radiator cap pressure and as a result was getting fluid pushed out of the header tank. That issue seems to have been put to bed with the correct radiator cap. I do love my G but you have to watch her closely - she has done over 300,000 km so might need a little extra tlc every now and then :)
 
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