Crank, No Start and Coolant Leak Double Whammy

[Clipper]

Reporting back after a long weekend. So I put in new NGK spark plugs and it fired right up. I am hoping that replacing the ECT and thermostat will solve the crank, no start in really cold weather for the future (this also happened two years ago after prolonged sub zero temps).

I had no coolant loss while it was just sitting. After start up it began dripping from the passenger side, rear corner of the radiator and I could clearly see where when I looked at all the sludge in the splashguard. Should I look to replace the hoses closest to that spot or plan on replacing the radiator?

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When I was looking over the car before I found a torn vacuum line (coupling piece) coming off the intake manifold hidden behind the power steering pump. I'm hoping replacing that will remove the persistent P0172 code.

After researching the PCV system a bit on this board with the car running I pulled the dipstick out a few inches and saw white smoke coming from the dipstick tube (I didn't do the "glove test). Would replacing that torn vacuum line coming from the intake manifold clear up the smoke or should I plan on having the whole PCV system serviced?

[erikv11]

The coolant leak I can't tell. I would keep trying to figure it out. For that location it must be either the upper coolant hose or the radiator. Common trouble spots are the radiator seams and the neck where the hose connects. But if the coolant hose is ancient then you will probably want to replace it anyway.

That elbow is almost always the cause of the P0172. I would fix it (I like to just use a long piece of vacuum tubing, replace the whole line), then do a glove test on the PCV. A little white smoke at the dipstick doesn't really mean anything if there is vacuum on the glove test. But longer term, assume the PCV needs done either way. If the elbow is that bad, many other rubber vac lines are too. I would also plan to go over all the vac lines soon, and replace what is rotten or soft.

[Clipper]

So would you replace that short piece or would you run it all the way to the PTC? I did some digging on here and saw some people running it to the PTC which seems like a good solution, I was just a little unclear on the process. Looks like I should do a little more digging.

[erikv11]

Yes, the most certain way to repair it is to run a line all the way to the PTC. For example, there could be another break in the line somewhere, then the elbow wouldn't fix it. This old post documents the basic idea very well: https://www.matthewsvolvosite.com/forums ... hp?t=47383

If you do a new line all the way, just leave the old hose in there until you eventually pull the manifold for a PCV job.

[Clipper]

Would anybody know off hand If I'll need any fittings to get the vacuum line over either end? Also what should I use to secure it to either end? Hose clamps? Zip ties rated for engine heat?

[erikv11]

No extra fittings needed. If you use 3/16 ID line then the fit will be tight at the manifold end (lubricate it by dipping the end into isopropyl alcohol, then use very long nose pliers to put it on) and on the loose side at the PTC end. I would secure it with a zip tie at the manifold (easier in the tight space, and less securing is needed) and a little screw clamp at the PTC end. Be careful to not break the plastic PTC nipple.

[Clipper]

Thanks for all the help, I'll tackle it this weekend. The dealership didn't have the ECT in stock but I should be able to get it from my indy Volvo mechanic tomorrow (and hopefully pick his brain a little too, I'll probably bribe him with a six pack...)

I figured I'd drain the coolant, remove the radiator hose, change out the thermostat and ECT, connect the vacuum line to the intake manifold all at once, then route the vacuum line to the PTC. Should I pull and clean the PTC or just connect it up?

I should also mention that I did the glove test and the pressure caused it to inflate.

[erikv11]

Sounds like a plan. The nipple on the intake will be much easier to deal when the hose and upper t-stat cover are off.

If you have the time while you are in there, cleaning the PTC is is a great idea. Noting how clogged up it is (or isn't!) will also give you some readout on the rest of the the PCV in general. It can be difficult to get the PTC back into the intake pipe but it will go in. Since the glove is up I think I would definitely do it, then check again once you are all finished.

[tannibanani]

I found the leak on my C70 1999, it was the radiator. RH side (pass. side) where the metal meets the plastic. I took it to Volvo mech. and he told me to replace the radiator. He also told me to try radiator stop-leak but I'm not so sure about that...

Hope that you can find and fix yours.

[Clipper]

To report back:

We went to work on the two bolts on top of the thermostat housing and promptly cracked the housing by tapping on the top of the socket wrench, ordered a new one and waited until Monday. On Monday we got to work and moved the power steering pump and replaced the housing, thermostat and ECT. I didn't bother to ohm the ECT but the thermostat did show signs of wear and rubbing as well as a small crack on the top portion. I replaced it with a Volvo thermostat dated 1995 I found hidden in the back of my wagon.

We replaced the hose going from the intake manifold to the PCV system while the thermostat housing and power steering pump were out of the way. There was also another torn hose on the PCT end of things. I cleared the P0172 code and it hasn't returned as of yet which is amazing because it's been on forever. Some extra MPG's would be amazing.

Big thanks goes to Phoenix Foreign Cars in Madison, WI for all the help. If you live in the area Bob is an awesome mechanic and a great dude.