Pressurized radiator on cold engine

abittenbinder

Doktor A (864-623-9110)
Typically a head gasket issue.

While the cold residual radiator cap pressure and coolant loss are typical symptoms, misc. other circulation related issues may exist.

Among those are erratic heater operation and a unique one recently- an '05 owner comes to me with a defective EGR valve and reports he has replaced 4 in the last 2 months. The EGR seller on EBay kept faithfully sending him warranty replacements!

That is indicative of EGR valve damage from localized overheating due to lack of coolant circulation in the EGR cooling circuit. Yes, the EGR coolant circuit does more than intake charge exhaust flow cooling, it also keeps the valve alive and well.

Moral of the story- combustion gas leaks into the coolant circuit can disrupt coolant flow in far flung branches of the system.

Doktor A
 
Typically a head gasket issue.

While the cold residual radiator cap pressure and coolant loss are typical symptoms, misc. other circulation related issues may exist.

Among those are erratic heater operation and a unique one recently- an '05 owner comes to me with a defective EGR valve and reports he has replaced 4 in the last 2 months. The EGR seller on EBay kept faithfully sending him warranty replacements!

That is indicative of EGR valve damage from localized overheating due to lack of coolant circulation in the EGR cooling circuit. Yes, the EGR coolant circuit does more than intake charge exhaust flow cooling, it also keeps the valve alive and well.

Moral of the story- combustion gas leaks into the coolant circuit can disrupt coolant flow in far flung branches of the system.

Doktor A
Can you change a head gasket in place or does the engine have to be pulled?
 

owner

Oz '03 316CDI LWB ex-Ambo Patient Transport
Yep I can confirm circulation related issues. I have this pressurisation issue on mine, and I can hear the pockets of air flowing through the heater circuit while driving. Fortunately I don't have EGR. I have put in a bottle of K-Seal (https://www.kseal.com/au/) to see if that will fix it, but I'm not confident, since the crack/hole is under reverse pressure so the coolant/K-seal isn't being forced out of the crack because of the pressure coming in from the cyl. I tried to help it as best I could by allowing the hot engine to sit shutdown in REST mode using the Espar to circulate hot coolant without the engine continually pressurising the system. Will report back on the outcome when I check for pressure next week.
 

abittenbinder

Doktor A (864-623-9110)
Can you change a head gasket in place or does the engine have to be pulled?
A head gasket can be replaced in place but Best Practices and best quality outcome (as well as possible additional damage surprises) really demand that the engine is out of vehicle.

It will save time and money in the end.

Doktor A
 
A head gasket can be replaced in place but Best Practices and best quality outcome (as well as possible additional damage surprises) really demand that the engine is out of vehicle.

It will save time and money in the end.

Doktor A
Would that be pulling the engine and transmission out as one unit?
 

abittenbinder

Doktor A (864-623-9110)
Would that be pulling the engine and transmission out as one unit?
You can remove the transmission first (and mate to engine before re-install) OR remove them as a unit.

But do not risk damage to the transmission's oil pump, t. converter seal, etc. by removing just the engine.

Doktor A
 
You can remove the transmission first (and mate to engine before re-install) OR remove them as a unit.

But do not risk damage to the transmission's oil pump, t. converter seal, etc. by removing just the engine.

Doktor A
I only have 180000 kms on the sprinter. After my 18k trip last summer the low coolant light came on. It has been getting worse in the last 8k kms.

I was planning a 2k trip next week. Still trying to figure out how I could use the van on this trip and fix it on return. I know it is not right but tempted to try to seal the leak so I can make the trip.

I can see how the compression pushes the pressure in, I'm surprised it doesn't bleed off back through the same place. If the sealant can't feed back through the same spot then it wouldn't work.
Still not sure where the antifreeze is going. Out the exhaust ( haven't noticed anything)or out the overflow tube ( nothing dripping or on the ground). I originally thought it was a small leak related to the espar or hoses.

I'll remove both as one unit.
I will be asking for help on what has to come off and what can stay on and be removed with the unit. I'll probably ask a semi retired mechanic friend to help.

What can I get for a manual and is it online so I could print it out?
If anyone know specific threads that would outline engine removal would be appreciated.

Thanks
 

owner

Oz '03 316CDI LWB ex-Ambo Patient Transport
I can see how the compression pushes the pressure in, I'm surprised it doesn't bleed off back through the same place. If the sealant can't feed back through the same spot then it wouldn't work.
Still not sure where the antifreeze is going. Out the exhaust ( haven't noticed anything)or out the overflow tube ( nothing dripping or on the ground). I originally thought it was a small leak related to the espar or hoses.
Yeah thats why I ran my sealant through the system using the espar after it had been pressurised, to give the sealant a chance of being forced back out the hole. There is a lot of pressure when a cylinder fires, I would guess thats when the air escapes into the coolant, and helps explain why the coolant isn't going back into the cyl so much. All it needs is a tiny pinhole of a crack.

My theory about where the coolant is going, is that is it being gradually evaporated out with the escaping combustion air out the overflow breather. Mine also has no traces of coolant around the cap/breather.

I opened the cap on mine yesterday for the first time since putting the K-seal in this time last week. There was still a big burst of pressure released, which I was expecting. The real test now is if it still has pressure the next time I pull the cap. Will give it a few days and report back. I can still hear cavitations in the heater pipes, but it seems to have reduced a lot during the week. Fingers crossed.
 

NORTON

Member
I have the MB documents for engine removal and install for the 612.981 sprinter engines
If useful to you I can scan and email
 
Yeah thats why I ran my sealant through the system using the espar after it had been pressurised, to give the sealant a chance of being forced back out the hole. There is a lot of pressure when a cylinder fires, I would guess thats when the air escapes into the coolant, and helps explain why the coolant isn't going back into the cyl so much. All it needs is a tiny pinhole of a crack.

My theory about where the coolant is going, is that is it being gradually evaporated out with the escaping combustion air out the overflow breather. Mine also has no traces of coolant around the cap/breather.

I opened the cap on mine yesterday for the first time since putting the K-seal in this time last week. There was still a big burst of pressure released, which I was expecting. The real test now is if it still has pressure the next time I pull the cap. Will give it a few days and report back. I can still hear cavitations in the heater pipes, but it seems to have reduced a lot during the week. Fingers crossed.
I'm at the same spot that you are. I plan to run it through some heat cycles and see what happens.
I also fastened a juice bottle to the overflow hose.
 

owner

Oz '03 316CDI LWB ex-Ambo Patient Transport
Well the K-seal didn't work for me. Still getting pressurized coolant system after running the k-seal for 2 weeks and even running it via the espar.
 

Geoffreye

New member
I am experiencing the same problem with pressure in radiator. Have you ever located the source of this problem? Was it a cracked head, gasket, or other issue?
 
I skimmed through all the posts but didnt see this...have you put a new thermostat in? odds are its not the problem but its a very inexpensive part to throw in and they can fail in weird ways causing intermittent issues.


but headgasket does sound like its in your future.
 
My head gasket was blown by #4 cylinder to the water jacket.
I replaced the gasket, head bolts, injector hold down bolts, seals, thermostat and fuel filter.
Plan to do the viscous fan and radiator hoses at a later date.
I changed the turbo resonator for my Dorman spare and put the original under the seat.
The job wasn't hard, no special tools, just Torx sockets.
Didn't spend a lot of time inspecting the head for warping after cleaning.
So far so good it is working fine, I realize my old thermostat was not working. I run 86c all the time now. The old one would only go that hot on the highway not around town.
I bought all Malhe parts from rockauto and the prices where reasonable.
You will need a good inch lb torque wrench and a way to measure 90 degree on the head bolt tightening sequence. A bottom 6mm tap would be worth having, I made a thread chaser from an old hold down bolt. I could have used a bottom 8mm tap for the one bolt that broke on the turbo, but made due with a regular tap.
Another bonus is you will know where all the sensors are and how everything works in conjunction with each other.
 

Trackbum

New member
Hey Flatheadfever, did you do the head gasket with the engine in the van? Can you give a more detailed write-up of your process? I'm thinking I may try to tackle this in the near future.

Also, how do your temps look on the stock gauge now that you've done this work?

Trackbum
 

PATECO

Member
RON234,

I am having a similar issue with my Van, but with some signifigant differences

Here goes:

Your basic 2004, 2500... low top Cargo. 299,578 miles (should hit 300,000 this month)

1) In the morning after Sprinter has cooled down, if I check the coolant, Very little pressure, and I think it is negative no splashes. If I open it up after a long drive, there is some positive pressure, but no splashes or gurgling.

2) There is NO OIL in the radiator fluid.

3) There is no water/white stuff/emulsion in the oil (I change it myself... 3 x's now...nothing, ever)

4) No white smoke out the exhaust.

5) I have been losing coolant... Started out small, having to add a quart every 6 months. it has been getting worse over time. Now I am putting at least 2 quarts or more into it every couple of weeks.

6) The coolant light which used to come on every couple of months usually comes on now within a day or two after I've topped up.

7) No leaks on the ground under the van

8) I looked for white residue indicitive of a leak on the engine somewhere... nothing I can see... , but the bottom of my engine is pretty dirty.

9) Van temp gauge say I am running just under the 180° mark. it will go above 180° if I have been pushing her hard on the highway.

I know this is something I can not just ignore? I don't want it to be causing problems.

I have plenty of power... Most driving is a mix of highway and city miles. I'd like to solve it now if possible

THANK YOU!
 

SneakyAnarchistVanCamper

Reading till my eyesbleed
RON234,

I am having a similar issue with my Van, but with some signifigant differences
Try replacing radiator cap with the proper OEM MB part? The coolant system is pressurized under normal operation, relieved only by the rad cap. A faulty rad cap can cause overpressure. Start with the simple and cheap things first. Worst case scenario, you now have an emergency spare and one possibility crossed off.
 

Trackbum

New member
Try replacing radiator cap with the proper OEM MB part? The coolant system is pressurized under normal operation, relieved only by the rad cap. A faulty rad cap can cause overpressure. Start with the simple and cheap things first. Worst case scenario, you now have an emergency spare and one possibility crossed off.
I've done that, but it didn't help. Looks like a head gasket job is in the near future. I don't really want to pull the engine and trans out so I may try to tackle the job with engine in the van. Anyone out there done that? If so what info can you share?
 

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