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My car when cold starts normal and temp slowly raises as normal.
But at first time reaching the middle, goes little over it (3/4mm) then immediately falls down to middle and doesn't move from there in any case, never.
This behaviour appears only on cold startups.
So today I took the old lady for a ride: about 50 km return on the motorway, state road and hills, Ikea ( -.- ) and on the way back we climbed up over a mountain nearby, in order to "test" the engine on a more stressing situation on a steeply uphill road full of hairpin bends and to have a pause for a coffee before taking the road again highway heading home.
Average temperature 38° outside, the needle never moved a moment from the center as normal, even going up the mountain.
Only thing I had to notice is that as soon as we arrived, making maneuvers looking for a parking space, the idle was a bit unstable and same when we left, car wanted to shut off even with some choke, issue that was resolved after a few metres and idle turned normal: certainly the engine was "stressed" and hot, humidity was quite accentuated and there was something that car didn't like after that street, someone can help me understand what to investigate?
Anyway I will change the thermostat regardless and the 4 pipes that I see between the radiator and the tank but today's experience reassured me that the temperature management does its job anyway: maybe the issue on startup is only a "tired" thermostat?
My Volvo is a 1981, B19A engine with Zenith-Stromberg carburettor
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Hi,
From the reading I would say you are putting too much emphasis on the thermostat having an issue.
We do not know the mileage or the condition of the engines oil control rings but driving through hairpins on a mountain grade will change the vacuuming above the pistons.
This will make oil be pulled up past all the rings where on the level driving of hairpin roads would not.
Engine braking makes the vacuum level be at its highest with a closed throttle.
I think you should take a look at the mixture deposits on all of the spark plugs.
While you have them all out do a compression test too.
Use those numbers from each cylinder and see if anything might match up to any one certain plug of oil burning color or oil fouling contamination.
Reset the plugs gaps to .028 if they are wider than recommended.
If you are using oil on a cylinder, more than any others, you can try using a spark plug that is one level UP on its heat range index. Especially, if you like doing lots of sport driving that involves jumping on and off the throttle.
It cannot hurt anything to vary a spark plug(s) heat range to get a more optimum burn.
That is unless you ran your engine at its maximum output for a long enough time to make them cause pre detonations or in extreme cases to burn a hole in a piston, like in racing competition.
If your engine might be aged with mileage or oil break down some other adjustments can be made.
Carbureted vehicles are running under a mix of compromises to average some “spot on” mixtures all the time anyways.
Having access to the choke function, cold temperatures and the changing of altitudes just exacerbated the built-in compromising.
Idling an engine is at one extreme end of an engine’s performance spectrum and is more noticeable than one misfire at higher continuous RPM under a light load. The momentary reduction of power is easily not noticed until the power level drops significantly as if one cylinder not contributing. A mass number of cylinders can even mask that.
When you have only a one cylinder engine you know it instantly a misfire.
Awareness decreases enough that with twelve cylinders you might think it’s an electric motor or like a ceiling fan in your house.
Those can have up to 24 magnetic poles in a circle that makes it run slow on 60 hertz or @ 150 rpm on low.
Tie some poles together and it speeds up or down but the blade’s tip diameter demands it be kept low.
Ever notice the rim sizes on our cars get bigger but the tires are relatively the same ?
It’s a marketing eyeball game within its physical limitations. Same load capabilities.
I do not know what the record is for that maximum number of cylinders in a petrol engine in a car.
Stationary engines are plentiful.
I have stood beside a running 12 cylinder diesel before.
I was told it had the NORMAL 10 inch pistons. Normal?
Never mind the stroke as hearing protection was required inside building with it. 😬
Then there are locomotives that are heard for miles or earth movers that are huge too?
Oil consumption, who knows as stationary engines run at constant speeds and the loading is kept as even as possible. Oil changes require pumps from oil drums.
Oh well, this was more than you asked for but changing the thermostat might be as equally equivalent to shaking a grease rag in the wind. Nothing is going to change with the rag.
It is just my entertainment at the moment too. 😊
Phil
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Hi, thanks for the complete response! I'll try to answer you as clear as I can... due to my limited technical english.
A little premise.
Car was my dad's garage princess and buyed it in 1981 brand new. Dad have ever cared it till his passing last year and was always "his car", I drove it 3 times in my life till last november. So I have no knowledge in this car but I want to preserve it like he did the last 43 years.
Car has 106000km (65000 miles), completely stock.
Had radiator repaired (I think) 20 years ago, brand new water pump, coolant to be refreshed (think 3-4 years).
No oil leaks, no coolant leaks (after changed water pump for a little trasudation).
Carburetor was revised approx. 5/6 year ago as far as I know due to a difficult hot engine startup and "hiccups" (what I know).
**From the reading I would say you are putting too much emphasis on the thermostat having an issue.**
Thermostat is the original one as far as I know. Even if can be perfect, a refresh will be considered ordinary maintenance, with rubber hoses too even if in good shape
**We do not know the mileage or the condition of the engines oil control rings but driving through hairpins on a mountain grade will change the vacuuming above the pistons.
This will make oil be pulled up past all the rings where on the level driving of hairpin roads would not.
Engine braking makes the vacuum level be at its highest with a closed throttle.**
mileage as said 65'000. That oil pulled up past all the rings may leak somewhere/can be checked?
A thing I noticed yesterday after that issue was a little oil in the part I highlighted in blue (is a pic taken some times ago, just to show position).
maybe is related?
**I think you should take a look at the mixture deposits on all of the spark plugs.
While you have them all out do a compression test too.
Use those numbers from each cylinder and see if anything might match up to any one certain plug of oil burning color or oil fouling contamination.
Reset the plugs gaps to .028 if they are wider than recommended.
If you are using oil on a cylinder, more than any others, you can try using a spark plug that is one level UP on its heat range index. Especially, if you like doing lots of sport driving that involves jumping on and off the throttle.
It cannot hurt anything to vary a spark plug(s) heat range to get a more optimum burn.
That is unless you ran your engine at its maximum output for a long enough time to make them cause pre detonations or in extreme cases to burn a hole in a piston, like in racing competition.**
this car is and always was a "sunday trip car". SO nothing that can have sport in his word has ever seen it -.-
Spark plugs can be old too as far as I know: maybe not so ruined but surely old. Thanks for the suggestion.
**If your engine might be aged with mileage or oil break down some other adjustments can be made.
Carbureted vehicles are running under a mix of compromises to average some “spot on” mixtures all the time anyways.
Having access to the choke function, cold temperatures and the changing of altitudes just exacerbated the built-in compromising.
Idling an engine is at one extreme end of an engine’s performance spectrum and is more noticeable than one misfire at higher continuous RPM under a light load. The momentary reduction of power is easily not noticed until the power level drops significantly as if one cylinder not contributing. A mass number of cylinders can even mask that.
When you have only a one cylinder engine you know it instantly a misfire.
Awareness decreases enough that with twelve cylinders you might think it’s an electric motor or like a ceiling fan in your house.
Those can have up to 24 magnetic poles in a circle that makes it run slow on 60 hertz or @ 150 rpm on low.
Tie some poles together and it speeds up or down but the blade’s tip diameter demands it be kept low.
Ever notice the rim sizes on our cars get bigger but the tires are relatively the same ?
It’s a marketing eyeball game within its physical limitations. Same load capabilities.
I do not know what the record is for that maximum number of cylinders in a petrol engine in a car.
Stationary engines are plentiful.
I have stood beside a running 12 cylinder diesel before.
I was told it had the NORMAL 10 inch pistons. Normal?
Never mind the stroke as hearing protection was required inside building with it. 😬
Then there are locomotives that are heard for miles or earth movers that are huge too?
Oil consumption, who knows as stationary engines run at constant speeds and the loading is kept as even as possible. Oil changes require pumps from oil drums.**
this kind of setups/modifiy is little "too technical" for me but you was able to make me understand them :)
*Oh well, this was more than you asked for but changing the thermostat might be as equally equivalent to shaking a grease rag in the wind. Nothing is going to change with the rag.**
as said, this rag is more than 40 years so maybe is time to change it to one that's trendy today :p
My next steps for this behaviour will be, being preventivate maintenance too:
- check and eventually change spark plugs and spark plug wires.
- check accurately if there are misfires at idle
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Hi,
Oh my gosh I almost hate to tell you this but your engine isn’t broken in yet.
It takes somewhere up around 100,000 miles to wear-in red blocks.
You need about twice that mileage to get things fitted up internally.
The engine’s valve cover looks like my 1978 2.1 engine.
That spot is a normal sweat area as oil lays up in that corner of the head full time because the drain hole at the rear is farther inboard.
All these engine use cross laid fiber material so expect some seepage or weeping vapors to come through.
Some would suggest running a torque wrench over the set at the maximum recommended pressure but there are two theories on that it could help or make it worse. It can happen just as easily with a new gasket over time of which you have plenty of that going on.
Letting the car sit that much is like early retirements that can be detrimental to humans.
Even harder to as to be diagnosed.
That is saying there are so few of them kicking around that as there’s no backlog of what happens to machinery treated like that.
Were the cylinders ever fogged against getting rust of the bores?
Did the car ever sit for long periods of like a year plus?
When it was driven, did it get throughly warmed up?
It takes about eight miles to give them some of that used feeling.
The engine will have to be run to scuff things up a bit and get the rings clear of oil gumming varnishes of that era. Todays oil will help that take place.
How did you keep the carbs from getting mucky inside?
Todays fuel in the USA has a small amount of alcohol in it and sometimes it attacks the metal of certain variations of the cast metal their made of.
It not a heavy duty problem as detergents are compensating for most of those affects.
The fresher the gasoline is kept the better period.
Volvo or Bosch made their fuel lines better than domestic cars on the car despite still using carburetors.
The K JETS paved the way I suspect.
As far as the thermostat my 1978 and 1984 on came with al brass WAHLER brand. I alway try to get those but Borg Warner made the 92 degrees one that if you can find them are like hens teeth or NOS.
The product that ART talks about is one I have a lot less trust in but everyone pushes them through chain stores. The don’t seem to stay as accurate to me and cause the “waffling” of the temperature needle.
I have had those goes bad ( luckily fail open) long before the WAHLERS that are dated by the manufacturer that tells me how long they were in the car.
If you take yours out, look for brass construction and a date.
You might want to change the gasket ring anyway and put it back in.
They are hard to get and my 1978 had a 92 C but it was a California approved smog car. I have it in a used box too!
Those bubble pack thermostats, in stores, are bad news. STANT started that! I had lots of them fail on my FORD truck before I got my 1978. I won’t touch a STANT in a store with a dirty stick!
These items should be treated as precision instruments. IMO.
There’s a theory, mine, that goes with all I have said and not stated too.
Chain stores are doing the wrong things to us.
IMHO it’s for extra profit, for less inventory with likewise more ROI.
Consolidating and downsizing are used in the new warehousing businesses buzz words.
Thanks for the compliment and for reading and using the Brickboard with its ailments.
Phil
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eheheh our car is and always was a "sunday car", used in the 80's and 90's for family holidays and then for the sunday drivers of my parents, so has never been driven so much. Never totally left not driven but on the last 5-6 years the car covered an average of 800, 1000km a year.
For the valve cover today while I was making inspection I asked the guy in the shop what could be and he found the bolt a little loosened (at 102.000 km was made valve registration, I think 4/5 years ago). So he put a new washer then tightened to spec (the other ones were ok). Let's see if this little dripping disappear.
Nothing ever made to cylinders because the cars has always run fine, never overheated, never lost oil (not so much to need to be refilled between oil changes), never lost coolant significantly: we discovered the water pump was leaking only because there is a corrugated cardboard under the car to cover some stuffs and we found 3 little drops...not too much to be noticed in the reservoir level.
For the carburettor: was revised 4 years ago but the car was used less and less as my fathers health went worse.
And yes, I know that using it more is the best thing to do: apart from the whim the other day described above the car goes much better and turns more powerful in these last 5-6 months in which I've been using it more frequently.
for the thermostat here's the thing I talk about: goes to the point of the 1st when started from cold then immediately goes to the center, and doesn't move from there anymore. Thaks for your precious suggestion on brands and types!
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Hi,
The thing about the thermostat is absolutely normal as it is called “overshoot.”
All thermostats have this trait because it takes reaction time in response to “change of state” of a medium that the thermostat is monitoring.
It takes time to shut off the burners, the turning off a relay or in the case of an electric heating element the heat is still on the way out of the rod or an reaction of infrared radiation.
You are not going to get way from it in almost all cases of monitoring resolutions used. In fact it was tried with the Temperature Faker that Art Benstein speaks about.
Trust us, it’s best to see that than not and adjust the brain to know it’s OK!
Despite what we think we want is “perfection” it is not obtainable.
The planet and the whole cosmos is going to adjust to keep things changing.
Evolution is learning to flex to the flux.🙃
I’m at a point in my life that I stopped flexing and have turned into being more like a fluid with some tolerable turbulence stirring in the middle, since I’m human. 🤭
It’s really nice to know when you only have a few oil drops on a 40 + year old vehicle.
If you didn’t have those or at least sweating stains, it would be like people denying they have never peed in a shower.
If I hear that, I know I just witnessed a fibber’s frail consciousness.
I tell them it’s all goes in the same drainage system. 🤔😊
Phil
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:) :) :)
no oil...no joy :)
my concern is only because I don't know if the car has always done this way or not or is related to a thermostat become weak after 40 years, even if not "used a lot".
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Hi,
If you are so concerned about the thermostat you can go ahead and yank it out and test it. This way you will find out what brand and it temperature rating.
If it’s the original and so forth.
I use vegetable oil as it will heat the thermostat more evenly up to its set point in degrees centigrade. You can watch it better in my opinion to see when the disc actually cracks open at the required set point.
When using boil water it gets steamy and bubbles form and then you have air around the responding element that’s actually a wax pellet contained in a cylinder.
The bottom of your pan can affect the element so you want to suspend the stat in between the top and bottom.
The Oil, IMO disperses any radiant transfer more evenly because of the lack of entrained air molecules.
The energy involved is like light or a radiation wavelength . Through air it can move faster towards an object.
So even if the thermostat is fine you can learn from doing and observing like many scientific types being mechanical inclined appreciate not having to say “I saw it all on Television, so it must be true!
A John Fogerty song lyric.
😊 in this case, in a cooking pan.🤭
Phil
Just noticed that I sent you a response to the Brickboard email from you to me. I thought it would post it but it did not.
So it must have died with in the web site somewhere.
I copied my response above from my sent box and got on here to post it.
Now I will try to see if the Brickboard stays up long enough for to post it our normal way before the shut downs.
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Are you saying the little dance above 9:00 on cold startup is suspect? In the US beginning '86 we got a compensation device called a Temp Faker to keep folks from complaining to the warranty service about that action -- that little dance. It is normal in every 240 I've owned or serviced where that Faker has been bypassed.
Notes on the Temp Faker - Or That Temp Comp Board
On the other hand, if you're speaking of the difficult idle or starting when hot, nothing you can fix by changing the thermostat, as it doesn't control the heating once the water pump stops pumping. Choke would make it worse, right?
--
Art Benstein near Baltimore
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Thank for your response.
No, thermostat and hoses will be changed because they're 43 years old and so as a consequence to see if it solves the behaviour at cold startup. We own car from it first day in 1981 but I drive it only from some months and I can't be sure if this behaviour is correct or not.
The issue at hot engine is not related obviously, sorry I was not clear but I'd like to investigate further what can be. Yes, choke seemed to make it worse.
Car has ever been perfect at idle with engine hot, this was the first time it happened and surely the mechanical being stressed was a cause.
For example...when back home I left the car at idle more than 10mins to set the minimum rpms, no signs of stalls .
As additional info, Water pump is new 😉
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Thank for your response.
No, thermostat and hoses will be changed because they're 43 years old and so as a consequence to see if it solves the behaviour at cold startup. We own car from it first day in 1981 but I drive it only from some months and I can't be sure if this behaviour is correct or not.
The issue at hot engine is not related obviously, sorry I was not clear but I'd like to investigate further what can be. Yes, choke seemed to make it worse.
As additional info, Water pump is new 😉
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Thank for your response.
No, thermostat and hoses will be changed because they're 43 years old and so as a consequence to see if it solves the behaviour at cold startup. We own car from it first day in 1981 but I drive it only from some months and I can't be sure if this behaviour is correct or not.
The issue at hot engine is not related obviously, sorry I was not clear but I'd like to investigate further what can be. Yes, choke seemed to make it worse.
As additional info, Water pump is new 😉
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Agreed it is a good plan to renew the original rubber and get a fresh thermostat. I think the original thermostats were Calorstat by Vernet, made in France, and the best in that era. I wouldn't be at all shocked if yours was still the original and by your description of its behavior, still operating like new.
From my experience, I recommend you find real Volvo heater hose, at least the S-shaped one at the head outlet. The aftermarket versions I've seen are not quite bent correctly, and may tend to rub on the oil dipstick tube. At least, be careful of this interference, especially if your motor mounts are as old as the coolant plumbing.
--
Art Benstein near Baltimore
The cardiologist's diet: If it tastes good spit it out. - Unknown
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thanks for suggestions. Motor mounts are in line for next visit on shop, while thermostat and hoses will be made by me.
If you can provide some good site to check out (skandix?) will be very appreciated.
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