omacdon2 wrote: ↑
Tue May 21, 2019 1:28 pm
... If not the head gaskets, I might just need to replace the radiator cap or it might be a tube leak.
If the PO was a mechanic, and a good enough one to do the swap, chances are it is not as simple as a radiator cap. Can't believe I'm posting this on an A/C VW site but here goes... basic checks of a water cooled system:
- Is the fluid low? Check the over flow tank for proper level (I'm assuming it has one). Top it off and keep an eye on it. If coolant leaks on the ground, you found your culprit. Or, if you can smell coolant out the tailpipe, or if it's billowing white smoke, then it's a head gasket.
- Is there milk shake like substance either in the coolant reservoir or on the dipstick? This wIll indicate mixture of oil and coolant...definite sign of a head gasket issue.
- do you have the right ratio of coolant to H2O? Buy one of those little tools that tell you (they are pretty cheap) and check it. It doesn't have to be spot-on, but it s/be close. IIRC, s/be good down to -40 degrees F.
- If there is air in the system it will also make the car run hot. Many modern (I use the term 'modern' loosely... I'd say mid 90's and up) have a bleeder port for the coolant system. Google your year engine and see if it has one. If it does, stick a small funnel in the port, turn on the car and let it run. Once the thermostat opens up, you will see bubbles out the top of the funnel (if there is air). Once it is done bubbling, all the air is out. turn off the car, put the screw back in the port, and top up the fluids to the appropriate level.
- If all of the above checks out, then the next thing I would do is replace the thermostat and radiator cap - don't skimp on the quality - get quality parts for these. Yes, you can run tests, but these parts are pretty cheap (even for quality ones) and bring peace of mind.
- Can you get a good look inside the radiator? Is it clean, or does it have a lot of scaley barnacles inside? If so, you need a new radiator.
- Next I would check for plumbing hack's/wonkiness to retrofit into the bus, as well as good airflow around the radiator as well as an electric fan that is operating properly.
- At this point, you may want to get it pressure tested; that can (I say can vs. will, as sometimes they don't detect the issue) determine if it has an internal leak..most likely head gasket, but some cars can also leak coolant around the intake manifold...I'm not familiar enough with Subbies to know if this is an issue or not.
-If the radiator checks out, the next thing I would check is the waterpump. If it is external, look for coolant weepage, that is a tell tale sign the pump is bad. If it is internal, then you may just want to replace it; internal ones are typically a PITA to replace (a good 3-4 hour job) and if you are going to spend that much time digging into it, you might as well spend the $75 to replace and have peace of mind.
EDIT HEY ADMIN: May want to move the thread from this point forward? We've segued from buyin' to fixin'