I like how he tried to avoid the big HG words…but he still said it in the end😂 Nice video, really good info on both reservoirs, definitely learned something new. Thanks!!
Hello FlatironsTuning this is a great video and has helped me hone in on my overheating problem. Although I am running into a unique situation. I have a 2010 WRX with 100k miles and my expansion tank fills up when the car gets to operating temp (195°F-210°F) but does not get pulled back into the cooling system once the car cools down. I live in Dallas so it's hot outside. I can drive for about 50 miles before the coolant in my engine gets too low(because it's in the expansion tank) and then the car will overheat. So I have to pull my expansion tank off and pour that coolant back into the fill reservoir (just above the turbo) every 50 miles to prevent overheating. This works but is not ideal LOL. My observations: 1. The coolant system does not lose any quantity of coolant. In other words I do not need to add more coolant to keep the system full. I just have to "manually" transfer the coolant from the expansion tank back to the fill tank. 2. When the car does overheat (due to low coolant in the engine) the top radiator hose is blistering hot but the bottom hose is basically ambient temperature. 3. No indication of bad head gaskets as there is no residue in either my coolant system or in the oil system and I am not losing any quantity of coolant or oil. Replaced Parts: New radiator (autozone), new OEM caps(high pressure cap on the radiator), water pump replaced 10,000 miles ago(autozone), new thermostat (autozone), Peaks Blue antifreeze. My WRX is basically stock except I have catback exhaust (and forester struts ;D). Intermittently code P0137 will come on (this is likely due to an exhaust leak as I have checked the voltage on the sensor while operating and it appeared to be in-spec). This does mean I am running rich all the time though. However, my intuition tells me that this should not have any impact on this particular cooling problem I am having but I'm not certain. My question: How would you go about diagnosing this problem or do you have any recommendations on what I should look for?
Thanks for your question, and sorry you are having trouble. Since coolant is not moving from the overflow back to the engine when it cools down, there are two possibilities. The first is that you have some kind of issue or leak in your cooling system that is preventing the vacuum from pulling the coolant back in. The second is that your headgaskets have failed. The best first thing you could do would be to have your cooling system pressure tested. This will tell you if you have any kind of leak that may be letting air in, etc. At the same time, it would be good to test your radiator caps just to be sure they are holding pressure. If all of that checks out, I'd recommend having someone thoroughly burp your cooling system to be as sure as possible that there is no air in the system and see if that improves or resolves your issue. If you do all that and the symptoms are still the same, I would recommend working with a mechanic to see what they would recommend as a next step, but it could well be that they would recommend replacing the headgaskets at that point. Hope that helps and Stay Tuned!
In the old days the coolant from expansion would just leak out the radiator cap but people forgot to check coolant and refill the radiator then they started using these expansion tanks and made them part of the system. They stuck them up higher then the radiator so no air would be introduced into the system. If you ever need to change these expansion bottle it’s easy you do not need to drain the whole system suck out the coolant in the bootle just enough so the bottle empty but not hose too the radiator just enough so you can remove the hose from the bottle. Replace the bottle connect the hoses refill the coolant you took out done you should not have to bleed the system. I replaced my bottle cause it got clouded from age and I no longer could see the level
Glad we could help! Definitely check your radiator caps and make sure they are working properly. If you are having cooling issues, you can't really start to diagnose the car until you know for sure that the caps are working properly. Best of luck and Stay Tuned!
So, what are some good aftermarket expansion and overflow tanks for those looking to move away from OEM? You mentioned the expansion tank should be at the highest point. I know IAG makes one that can be mounted where the boost controller is. And others use stock location. But can you clarify a little on overflow locations?
Thanks for watching and thanks for your question. I do like the IAG expansion tank, it is certainly one of the best options out there currently. For the overflow, size is really the most important part. I would not recommend going with anything that has a smaller volume than the stock overflow tank, and you don't want something that seals either. You need coolant to be able to fill up the bottle when it heats and expands with minimal resistance, and the tank needs to be able to hold the coolant that flows into it under all normal conditions. That is about it. I hope that helps and Stay Tuned!
Hey great video guys! Is the coolant expansion tank as important on a car running a non coolant cooled turbo? Something like a rotated setup where the turbo is only oil cooled
Thanks for your question Jake. If you have a method to bleed the coolant that has worked before, then I'd say you should be fine. Since Subaru's have the thermostat at the bottom of the radiator, getting air out from the radiator alone can be challenging. That would be my main concern. Hope that helps and Stay Tuned!
Thanks for the heads up Josh. We did have an issue with the audio in processing, but in listening to it again here, it sounds okay so far. We did just upload this, so it may take a little time to fully process. Thanks for watching and Stay Tuned!
If you are running a IAG AOS that runs coolant line you can use the as your high point one ej build on here do it all the time on his builds no issues and his car is 1000 plus
Thanks for your comment. That is true that with something like the IAG AOS, it does become the high point. And that can certainly make bleeding air out of the system harder if you don't address that. The Cobb version of the IAG AOS actually has a bleed screw on the top of the AOS for this purpose. With any AOS that uses coolant, you want to be aware of where the coolant goes in the can, and if you need to change your bleeding procedure to compensate for a change that the AOS may introduce. Thanks for watching and Stay Tuned!
My expansion tank is overflowing however I did the head gasket sniff test twice and it passed where you put it next to the exhaust and see if it changes color it was fine I have no milky substance in the oil tank and no milky or greasy coolant but yet my expansion tank keeps overflowing no indications of a bad gasket any advice
Thanks for the question. The first thing to do is to test your radiator caps to make sure they are working properly. Also that you have the correct caps in the correct location. Here is another video we have on that specifically: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-HzjBJz1Zdmw.html Hope that helps and Stay Tuned!
What an awesome and informative video. Keep going. However i am a bit concerned about my cooling system now, since i have lifted the tube, which leads down into the coolant expansion tank, a couple of times above the low coolant mark. Only for a very brief moment tho. Should i be worried that air might have gotten into the system? The car has no overheating issue.
Thanks for your question. If the tube has simply worked its way up, you should be fine as long as it is always sending coolant back to the engine when needed. If you aren't having any cooling issues currently, most likely you are okay, but you could burp the coolant just to be sure. Thanks for watching and Stay Tuned!
Thanks for your question. You certainly can. The idea of the staggered caps is that you can release the pressure from the Aux tank before the radiator. If they are both the same pressure, either one could open first. But it has been done many times without issue. You just want to make sure that both caps are holding the correct pressure. Thanks for watching and Stay Tuned!
That isn't the normal flow. It sounds like you might have air in the system, or a leak. I'd recommend pressure testing the system. Thanks for watching and Stay Tuned!
Great explanation! so, My son just ordered 2002 Subaru wrx turbo (basic 4dr sedan) a used engine (75K miles) to replace the blown up one. what things i should look for and what parts of the old engine should not swap? You know dads they want to make sure their kids don't screw up. BTW, engine arrived today and I noticed the expansion tank isn't there, so most likely would have to order one prior to installation, should I get a new or used one (in ebay)?. Sorry too many questions.
Thanks for your question. As long as it is a non-AVCS WRX engine, the swap will be very straight forward. If you aren't going to go through the engine too much, I'd recommend doing the timing belt service at a minimum. Re-seal the oil pump, and put on new timing components and water pump. That way you know all of those parts are in good shape, and it will also give you a good chance to look through the engine, etc. We have a blog talking about options here: www.flatironstuning.com/blog/what-is-the-best-subaru-timing-belt-kit The other thing I would say, because this seems to happen somewhat often, is, make sure it isn't an EJ20X or EJ20Y engine. We have a good discussion about that with iWire here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UkU8UqxDspc.html If the engine he got is a newer engine that has AVCS, then that is something that you will need to deal with and at that point I'd say the best thing to do would be to set up a consult with us on our website, and we can go through details for your build, and discuss options, etc. www.flatironstuning.com/build-consultation Hope that helps, and Stay Tuned!
2012 STi R Spec. Trackdays i find sometimes im getting some coolant blowing out. Is that from the high G corners or extra heat going thru motor?? i've checked all hoses and connections plus burped system twice to check. Running original coolant also as i've been advised by my engine builder against using other "better" brands
Thanks for the question. Have you checked your radiator caps? That is definitely the place to start: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-HzjBJz1Zdmw.html From there, you may need to take a look at your headgaskets. They can get damaged if you overheat the engine. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CZWPrsnxI-4.html Hope that helps and Stay Tuned!
As for the vid, you said its not okay if its close to overflowing, but how about if it looses coolant after every drive? Will that be fine? No overheating issues though after long drives. What i mean by loosing is that the coolant level is below the level i put coolant before i drive it
Thanks for your question. If you are using coolant, that is definitely something you want to check into. Your coolant level should not drop. If it isn't leaking, there is a chance it is an indication of a headgasket issue. Hope that helps and Stay Tuned!
My coolant gets really high but won’t overflow , and won’t go back down after cold engine changed rad cap already , running mishimoto rad no overheating
I'd say that it is worth double checking your coolant level. As discussed in the video, if your coolant is getting close to the top of the overflow, there is a good chance some is running out through the hole on the back. Hope that helps and Stay Tuned!
I heard that an "overflow tank" is next to the radiator and an "expansion tank" is the "highest point" of the coolant system located above the turbo. but I heard you call the "auxiliary tank" the "expansion tank" and you called the overflow the same.
Thanks for the question. More important than the starting point, you just want to see the level rise as the car warms up, and then go back down to the same level when the engine cools off. If you wanted to set the level in between the marks, you may want to use a marker to put your own mark on the bottle to see what the level is doing. Thanks for watching and Stay Tuned!
Hi there,i bought a radiator in Amazon and didn’t open the box to look at it,brought it to a mechanic to replace it,he replace it but the radiator is missing the nipple for the tank expansion hose.what can i do to fix it without charging the radiator again
Thanks for your question. That sounds like a radiator that is for a N/A car, not a turbo car. The N/A cars don't have the fitting for the expansion tank. I'd recommend returning it and getting the correct radiator for your car. Thanks for watching and Stay Tuned!
Doesn't the Subaru EJ cooling system essentially self bleed? Any air collects in the auxillary tank at the highest point, exits out the cap when engine warms and is pushed out via the expansion tank. I've never had any issues with mine or needed to 'bleed' it, like lots seem to.
Thanks for your question. In theory, yes, the cooling system will self bleed, but only to an extent. For instance, when you replace the coolant, and drive the car for the first time or two, you want to keep an eye on the "low" level, as it is common for the engine to pull in a bit more coolant as it does get some more air out of the system. That being said, if you start to have an issue with air in the system where the cooling system is starting to lose the ability to do its job, the system will more than likely never be able to correct for that. Hope that helps and Stay Tuned!
Thanks for your question. I'm assuming that is an oil only turbo? The auxiliary tank really does make it much easier to effectively get the air out of the cooling system. Thanks for watching and Stay Tuned!
Thanks for your question. Even with the turbo not being connected to the cooling system, the auxiliary tank still makes it a lot easier to get the air out of the system. Thanks for watching and Stay Tuned!
@@FlatironsTuning Quick question what happens if in between the fluctuatios of the coolant overflow tank(full and low lines) you have to put more coolant on the reservoir in like a weekly basis, like it has coolant and it goes higher as the engine warms up and expands then when it starts to cool down it drains the coolant but leaves less on the overflow as before it started . Is there something wrong with the cooling system? Oem caps on both radiators new and no sigh of headgasket issues already did a chemical test and passed fine. No overheating issues ever regular 3k miles oil changes with no milkshake mix 120k miles turbo ej25 2008 wrx.
@@joelsantana1249 If I understand correctly, you are saying that you have to keep adding coolant to your overflow? In that case, you are either leaking coolant somewhere (a pressure test of the system should show this), or you are sending it out the tail pipe (head gaskets). Ultimately, you need to find out where the coolant is going. Hope that helps and Stay Tuned!
Yes from time to i have to add coolant to the overflow for it to not get empty and get air into the system as you mentioned on the video what would a good way be to pressure test the system? Is there any UV dye you can use on the coolant to find the leak?
@@joelsantana1249 Pressure test works really well because it is typically pretty clear where the leak is. But if you can find a UV dye, that could be an option. With the pressure test, if the system won't hold a steady pressure, that would also indicate the degree of the leak you are dealing with. Hope that helps!
