Volvo 780, 2013 D13 eng. 500HP I-shift.

Bubbles usually mean air and that means air is leaking into the system. Usual cause is a leaking injector pressurizing the fuel and coolant system. You would need to have a pressure test done to determine the cause.

 

Engine won't come up to Temperature= Failed thermostat. Basic mechanics.


....The bubbles is a separate issue. Can be several things. Injector cups is one common Volvo issue.

But.... There are several sources of pressurized air that can be the culprit.


There are two issues going on with this truck.

 

Correct, the reason the system is under pressure is to raise the boiling point of the coolant.

 

True unfortunately the thermostat is an easy repair the other isn't that easy nor cheap. If it is just the injector hopefully it won't take long.

Off topic but do you think running injector cleaner once a month or so would help in keeping . I saw an earlier post that you use injector cleaner. I have only replaced the injectors once so far, and hope to keep it that way. What do you use?

 

Yes, i use the Amsoil injector cleaner concentrate once in a while.

The Volvo injectors spray at 35,000 psi .... When they start to clog up ... it takes enormous pressure from the camshaft to compress and squirt the fuel.

Of course what holds the injector into the head? The injector cups...... They get beat on pretty hard if the injectors are getting clogged at all.


Another problem with the injector cups on the Volvo motor is the temperature setting for the coolant fan to turn on ..... it is way too high. This causes additional flexing in the head from expansion and contraction ...which can compromise the cups seal...

 

Is this the product you using??

Diesel Injector Clean

 

Yes in 64oz bottle

 

Thanks. The dealer can program your fan to turn on at lower temperature.