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'72 164E time to pull the head?

srs4164

Active member
Joined
Feb 6, 2014
Location
CA, USA
Car has 57,000 miles on it. Been chasing a running too hot issue for several months now, which is getting more imperative with hotter weather coming. I've read about the tendency of these blocks to silt up toward the rear and fear that it may be time to pull the head to see about cleaning this out. Before pursuing this, which isn't anything I feel qualified to attempt myself, I figured it'd make sense to see if anyone has any other suggestion of something to try first.

So here's what I've done -

I've tried multiple thermostats and sensors, replaced the water pump, confirmed with a radiator shop that my radiator has no blockages, flushed the system with radiator flush additive and distilled water followed by distilled water only, gotten new OEM caps for the radiator and overflow tank and checked my compression (which was in spec) even though there were no signs of headgasket failure either in my oil or coolant. The timing is right on 10 degrees BTC. I'm not losing any coolant. I've confirmed that the voltage stabilizer (for the temp. and fuel gauges) and the temp. gauge itself are working correctly. Even swapped in a second instrument cluster that everything had tested OK on. With all this, the coolant has been replaced multiple times within the last 2 months and I'm using Zerex G5.

With an IR thermometer, I was able to see that there is a hot stop (as high as 234 F degrees) at the rear of the block next to where the rear head bolt is, which is only a few inches from the sensor for the temperature gauge. Along the rest of the head, between the valve cover and manifold, the temperature is around 192 degrees. Is it possible that this hot spot is effecting the sensor and that my car isn't really getting close to overheating though the gauge is almost in the red? I keep this problem in check by keeping my heater control valve wide open, but it'd be nice to actually fix this problem as I didn't even feel comfortable driving to Davis this year, which had been my goal. I also believe this could lead to failure of cylinders 5 + 6.

While all of my '71 164s (the most recent of which I owned 25 years ago) had a draincock by the oil filter, the '72 doesn't, so I can't back flush it there.

Time to have the head pulled? If so, I'm pretty sure that'll mean I'll have to replace the headgasket, so then won't I also need to make sure the head doesn't need to be skimmed first?

Suggestions? Have I missed something?

Thanks
 
Your IR thermostat reading would seem to indicate a problem there and you seem to have covered most of the cooling system.

Never mind the distilled water, have you flushed and back flushed the engine with a water hose with the thermostat out? I fought this this winter and my problem turned out to be a very clogged radiator. Radiator flush is nothing more than a weak acid and fine silca. Vinegar is a stronger acid at a tenth the cost.



I had a '71 and loved it.

1971%20Volvo%20164.jpg
 
Radiator shop tested the rad and proclaimed it to be "wide open". Was recored about 8000 miles ago and haven't ever detected any cool spots.
 
You might have a clogged water distribution pipe inside the cylinder head. The pipe has slots to direct water into the block which can become clogged, usually with excess silicone from a water pump installation.

FYI, I only use European made thermostats in my customers B18/B20/B30 engines and these thermostats are not generally available from most auto parts stores.

Where did you get your thermostat(s) and who made them?
 
Hello Eric,

Got one thermostat from you and the other from IPD, so they both had the jiggle valves. Talked to you on the phone a couple of weeks ago for your input which led me to confirming that my voltage stabilizer and gauges were both working correctly. Forgot to mention in my original post that I've also replaced my fan clutch and I'm pretty sure its good because when I stand in front of the grill my shorts will stick to it from the suction!

So I'm leaning to the water distribution pipe inside the cylinder head being clogged, whether by 'silt', silicone or whatever. How difficult is it to access this once the head's off? Should it be able to be cleaned out, or might it need to be replaced?

Sure wish I lived closer to your shop (it's just a tad too far from the Bay Area!) so I could bring my vehicle to you at this point. I suspect I'm going to have to hope to find someone "local" who's willing and able to help (for more than just beer! just throwin' that out there!) or a shop with a mechanic who's experienced with these (which I suspect will not be very easy to do!).

Thanks,

Stan Sirico
 
Hello Stan,

You might be able to remove the water distribution pipe without removing the head.

It is accessed through 1 of the 2 small core plugs on the front of the head.

I have never had to do this on a 164 with a B30, but I have on 122/1800/140 Volvos with B18/B20 engines.

You will have to pull the radiator and possibly the front grille to have enough room to slide the pipe all the way out.

And if you have A/C, you may have to move the A/C condenser.
 
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