Hello, I have a 2010 Prius and am getting the rattle on start up some mornings not all. I have cleaned the manifold, EGR, pipe. The car has 205,000. I know there is a replacement manifold that may fix this but have not replaced it. I have not had an issue until now with the old manifold. It maybe a head gasket going bad? The overflow in a years time has gone down only a half an inch. So I did a block test and turned from blue to green but not yellow like the instructions says. I should on a gas car turn to yellow and a diesel turns to green. I'm a little confused with the test results? Hate to put a head gasket in and not be the cause of the rattle. Any help would be appreciated. Thanks Gregg
EGR/Intake cleaning and oil catch cans, are preventative measures; they won't reverse the course of a failing head gasket. Another thing to try is a boroscope inspection. Look for coolant in the cylinder, and/or a steam-cleaned look to one cylinder in particular. When the head gasket fails it's often cylinder one. BTW, when was the cleaning done, recently? How bad was was it? I wouldn't bother with replacement intake; cleaning's as good as anything. You got the EGR passages, one per port?
Even easier than a leak down test is popping the lid on your coolant reservoir on the left side. If it sucks air in when you open it, that means coolant is leaking into combustion chamber due to blown head gasket.
It was cleaned about a month ago and passages were not blocked. Did not clean the Cleaned everything but the heater
The pressure in the tank will be there even after it has cooled. http://www.RedBullet.net https://ProjectLithium.com/?ref=mG0GE http://www.Pulstar.com http://www.PlugOutPower.com Use code 7373 http://www.hybridpit.com Use code azusa http://CatStrap.net Use code azusa
Thanks for the clarification. When I did the block test I did not here any pressure when I opened it up. So maybe the head gasket for now is OK. I'll purchase a scope to see if I see anything in the cylinder. I do a lot of repairs and have a lot of specialty tools but not a scope. Thanks
For really minor blown head gaskets that don't yet show much for significant symptoms the cap needs to have been sealed for a long time to get that classic "whoosh" type sound. What I like about that approach when I help people with diagnosis is that they're standing there and its the first thing I do and once they hear that noise...
Can you let us know what you decide to buy for a scope? As well as what options you considered? I'm particularly interested in the least expensive option and have you, rather than me, determine if its good enough or too cheap. ;-)
Looking at a scope on eBay for around 21.00 that plugs into my iPhone. I’ll let you know switch one after I test it out
Im not trying to sway you away from the HG, but what oil is in the engine?? I just bought my newest-to-me Gen3, this one has 84k miles and it rattled on startup every time when starting cold. Last oil change was 1,500 miles ago in November 2020 according to the sticker on the window, and the service history on the Toyota owners site. It was rattling on startup for a brief second, when cold. Drained out the oil with 1,500 miles on it, looked fine although seemed thicker than 0w20 that Im used to, refilled with 0w20 Mobil 1, and a new oil filter and the engine no longer rattles and is smoother than ever. I do not know what was IN that engine, but it either wasn't 0w20 (dealer bulk oil of a different viscosity, maybe 5w30 or 10w30?) or the oil was diluted or somehow became marginal
Thanks for the input. I'm do for an oil change in 1000 miles. I have always done my own oil changes with 0w20. Oil still looks clean. Winter get a little cold in Minnesota but is mostly in the garage. What started this was a startup outside, sitting for 3-4 days at o degrees and threw a code failed to start but it did start and did not sound good. When I get my scope going to let it sit over night and see if there's moisture in the head. Also change the oil.
Last year for a different project, I bought a digital boroscope ("inspection camera") on Amazon for like $70. Too bad you are in MN, I'd lend it to you, but it would be perfect for the job.
is your oil milky or under engine cap has milky goo ,if you start when very cold outside ,the start knocking will be worse if its bad hasket ,personal experience of bad gasket 2010 prius
