If I was experiencing the symptoms of a blown head gasket

What symptoms are you having, and how did you decide those were the only two possible reasons?

 

The best preventative thing I learned at here is to replace HG at the first sign and install oil catch can. Seems like you're running towards engine replacement



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Head Gasket.

How many miles?

 

A little early for head gasket. Good time to clean Exhaust Gas Recirculation and intake though.

A leak down test is good, to test head gasket integrity.

 

You won't find a dealer or non-dealer shop that will properly clean your EGR cooler. You could buy a used one, clean it yourself and have the shop swap it for you. They'd also need to clean the small EGR passages on the intake manifold while they have it off. When you ask them about doing it, they won't know what you're talking about.

 

DIY is pretty much the only way to go. Or owner support group, like @Raytheeagle and his cadre, one good example.

Toyota doesn’t want to know. Their solution involves waiting till it’s pretty much too late, when you’ve got warning light and/or the shakes, and THEN replace about a grand worth of parts, rather than just clean them. And then there’s the labour, maybe 6 hours?

Ideally there should be a gratis cleaning at dealerships, every 50K, my 2 cents. But that’s not going to happen.

 

To @Mendel Leisk 's point, DIY is the way to get this done.

Is the Roseville for your location the one just northeast of Sacramento?

If so, you are close to the cadre.

Thanks for the expansion of my vocabulary today @Mendel Leisk .

 

Well, if you've eliminated the head gasket, that leaves the shakes to be caused by ... whatever is causing the shakes.

I never did find what the cause was in my 2001 when it started making the same noise after 198,000 miles (cold start on a cold day, once in a while). But the head gasket was ok and, notably, there was no EGR in a 2001.

 

Again: leak down test.

 

EGR problems really can't cause a misfire on cold start because the EGR valve is never used / opened at idle (cold or otherwise). If it was some how sticking open enough to cause rough idle then it should do so all the time. Just enough exhaust gas (aka H2O and CO2) mixed into the fuel and air going into a cylinder under the correct conditions slows and "cools" the combustion process- preventing detonation and reducing NOx emissions) Too much exhaust will cause a misfire (or combustion that is so "slow" that it feels like a dead hole.

EGR clogging can cause misfire on a hot engine with part throttle and load (when the valve is open) This system has passages to carry exhaust gas to each individual intake runner. Normal engine operation leaves a film of oil and PCV residue inside the intake and EGR passages which gets cooked by the (still hot enough) EGR gases into a solid carbony mass. Layer upon layer build up constantly. When 1 or 2 EGR ports get mostly or completely blocked then all of the EGR flow (enough for 4 cylinders) goes to the remaining 1 or 2 cylinders, causing misfire.

Your miss on cold start COULD be the beginning stage of head gasket failure (or not). One test is to remove all the spark plugs and the radiator cap. Then one at a time bring each cylinder to exact Top Dead Center with valves closed. Use a compression gauge adapter hose (with the inlet Schrader valve removed) to pressurize the cylinder with around 150psi air. If it pushes coolant or bubbles out of the radiator then you have a leak.

Second test is to do a cooling system pressure test on a hot engine right after shut down. (this test requires a handheld pump that fits onto the radiator in place of the cap - pump it up to 13-15psi). Leave the pressure on it overnight (expect the pressure to drop some due to temperature drop). Remove the coils and spark plugs then inspect inside the cylinders with a videoscope to check for any coolant.

Or your startup miss could be anything else- weak coil or bad plug, sticky valve, bad injector, intake gasket leak, etc, etc.

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I’d argue that an engine with chronic Exhaust Gas Recirculation clogging is going to run hotter, which I suspect increases the odds of head gasket failure.

 

Only the failure to do any sanity check on the numbers involved never gets any less glaring however often you repeat that.

 

I’m not sure what you’re saying; I think that it’s nuts to postulate without exhaustive scientific method data to back it up? I’d counter that it don’t take a weatherman to know which way the wind’s blowing.

And meanwhile, the head gaskets keep blowing. I’m gonna keep on top of Exhaust Gas Recirculation cleaning, see how that goes.

 

We've had this exact same exchange enough times that you are certainly sure what I'm saying and both of us know it.

You are mixing notions of "run hotter" that you have enough mechanical savvy to know not to mix.

1. EGR does flatten and lengthen the peak temperature curve traced out in each cylinder during each power stroke. We agree on that, because that's what it's there for, to keep the peak temperatures below where NOx emissions are formed. So far so good.

2. With a little verbal sleight-of-hand, you convert that every time into "is going to run hotter", even though we both understand the engine has a cooling system with a thermostat, which easily controls temperature despite very large changes in heat production such as the difference between driving uphill and downhill.

3. You jump from (1) and (2) to where this "running hotter" is now to be the death of head gaskets. and you make this jump in post after post after post without ever doing the minimal homework to look up what temperatures it takes to damage head gaskets and how that compares to even generous estimates of the "running hotter" you might be talking about. You avoid even addressing the question of what happened to the head gaskets in all the decades of cars where no EGR was used.

That's a dodge, because you are not doing what a person who 'postulates' a potential explanation for something does. Postulating an idea is the first step in finding out whether it might hold water or not, and that's why a person brings it to a community to begin finding out. Such a person generally comes to the table having already thought of at least the first, most obvious questions that could be raised about it, and has maybe ducked into a library at least to come prepared to answer those, and then asks for additional questions others might see, and participates in further vetting the idea.

You are following much more closely the classic conspiracy-theorist M.O., stringing together just enough loosely-connected-sounding facts to handwave into a sort of "who knows, there could be something to it", which you combine with active avoidance of any effort to find out if there is anything to it or not. In the first instance (however long ago that was), that meant you coming to the table without having thought of the most obvious questions yourself. Since then, of course, it means you repost in thread after thread after thread while pretending you have no idea what the obvious questions are despite having dodged them dozens of times. You just rewind and post the same spiel in another new thread, pretending you can't guess what the obvious questions would be.