'04 V70 - Headgasket - extremely low compression readings

Faust · Post by **Faust** » 02 Aug 2017, 18:05

OK, the car is an '04 V70, non turbo, approaching 200K. It has all the symptoms of bad head gasket, bubbles in the surge tank, water in oil, rough idle when starting. Not interested in spending a lot of dough on the car, thought I would try Blue Devil. I emailed them and got this:
It sounds like you may be getting combustion/exhaust gases blowing into the cooling system and creating pressure. To give yourself the best overall chance of BlueDevil working successfully is to remove the spark plug from the cylinder with the leak; this will be the spark plug from the cylinder with the low compression reading. If you are not sure which one that is, you may pull all of the spark plugs and will notice one will have a white-crystal-like substance on it and/or may look dirty; this is the plug you should pull. Leave that plug out for the 50 minute idle in order to relieve the pressure from building up and thus allowing the product to seal properly.

If your vehicle only has a reservoir/overflow rather than a radiator cap, instead of pouring BlueDevil through the reservoir/overflow, with the car off and engine cold you should disconnect the top radiator hose and add the product there; do not pour BlueDevil into the reservoir. Once it has been added reconnect the hose and start the idle from that point.

Taking their advice, I pulled the plugs. Two were white ceramic at the tip, 3 were brown. Not happy I waited until t was quite cool and ran a compression test (dry) Results were 90 - 90 - 90 - 90 - 120. Two of the 90 PSi plugs were white, the remainder brown. What do you people make of this? Could I have blown that many holes in the gasket?

Seems to me this car will idle on three cylinders, based on my experience of having two coils fail almost simultaneously. I wonder if I can take their advice and leave the two "white" plugs out?

My compression tester is "quick connect", I wonder if I could hook up my compressor each cylinder and watch for bubbles in the surge tank.

Post by **jonesg** » 02 Aug 2017, 20:23

Might be a warped head or valve problems.
I'd pull the head and inspect, it don't cost anything.
Alum heads can be hand lapped flat by hand. Very simply done.
Did you have an overheat ?

Faust · Post by **Faust** » 02 Aug 2017, 20:32

Interesting video. I have a mill, but it would take longer to set it up than to do the sandpaper method.

Post by **jonesg** » 02 Aug 2017, 21:08

Faust wrote: ↑02 Aug 2017, 20:32 Interesting video. I have a mill, but it would take longer to set it up than to do the sandpaper method.

Then you know something about machining .
People often assume the big machines are needed for accuracy, its simply not true. The opposite can be true.
A machine shop will get it accurate enough but consider the best lathe bed$ are accurate down to millionths of an inch and they are hand scraped/lapped.

Another downside to using the mill is it puts metal shards into the ports because it cuts from above.
Wet and dry paper , glued to a sheet of glass , puts all the alum on the paper, cleanup is simpler.

Faust · Post by **Faust** » 03 Aug 2017, 03:57

Thanks for the reply. My SB 9" still has the fish scales from scraping.

At 198K and the usual Volvo problems of ball joints and a CEL that defies diagnosis and inspection coming up, plus a few new dents from pulling logs out of the woods; I am going to pull the two white plugs and try the Blue Devil. If that fails, I'll be looking for another Volvo.

Post by **abscate** » 03 Aug 2017, 04:01

I'm thinking try a wet compression test just to gather more data. Also , was battery in top shape, throttle wide open when you tested compression. 90 psi is really low

Faust · Post by **Faust** » 03 Aug 2017, 10:16

Yes, I thought the compression readings were extraordinary. I will try again wet, and no the the throttle was not wide open.

Post by **oragex** » 03 Aug 2017, 10:42

While a head gasket is rare on this engine, engine neglected engine can blow one. It may be too late know, but good to know these non turbo have an issue with the intake air thermostat causing the engine to run hot.

Faust · Post by **Faust** » 04 Aug 2017, 23:41

I solved the low compression problem. It turned out to be my HF quick connect compression gauge. It just seems to stick at 90 PSI.

Still haven't gotten anywhere, after pulling and replacing the plugs, it refuses to run, even poorly.

Post by **jonesg** » 05 Aug 2017, 14:17

Faust wrote: ↑04 Aug 2017, 23:41 I solved the low compression problem. It turned out to be my HF quick connect compression gauge. It just seems to stick at 90 PSI.

Still haven't gotten anywhere, after pulling and replacing the plugs, it refuses to run, even poorly.

That makes one wonder about the water in the oil? Did you misread the early symptoms?
I've experienced a bad compression gauge myself.

Start again, test for spark, then fuel.