Last post on Oct 08, 2012 at 8:29 PM
You are in the Subaru Forester Maintenance & Repair
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Subaru Forester, Wagon, SUV
#1 of 44 Valve/engine woes. Need advice.
Oct 28, 2008 (3:09 pm)
Hi. I could really use some advice, but first some background.
Let me first say that I love the Forester, and I'd buy another. My 2004 Forester 2.5X currently has around 68,000 miles and is less than five years old – it was taken care of very well. On a few occasions (before 60,000 miles), usually going uphill, my car would feel like it was about to stall, but the dealership found no problems. A little over a month ago, my car sputtered again, this time on a freeway. I pulled over before it stalled. It had to be towed. The code that showed up was a P0304. What the dealership found, via a compression test, was that an exhaust valve in the #4 cylinder was bent and basically dead. I did not touch nor change the timing belt. I knew this would be an expensive fix. (Interestingly enough, I had this same code pop-up before my 60,0000-mile warranty was up. The previous dealership service dept. changed the sparkplugs.)
I was out of warranty (68,000 miles), but upset. I had taken great care of my car and never missed regular maintenance. I’m sorry, a car should not crap out on you like this, and the dealership service dept concurred. Despite this, my only chance was to talk directly with Subaru. The dealership mentioned that they might extend a “goodwill” gesture where they would cover some of the cost. Subaru asked for all my maintenance records, which I kept. After handing over a copy of all my records (40+ pages!), I received a call from the service department saying that Subaru would cover the cost of the repair! All I’d have to do is pay for the part ($300 timing belt). I was ecstatic – faith restored. I knew I had taken good care of my car, and Subaru agreed (but, of course, took no responsibility/blame) – this ailment was a rare occurrence.
The repair itself was intensive. They sent part of my engine to the machinist to redo the valves. It took about a week. I was a happy camper.
Flash forward, about two weeks, to last night. I start my engine and the check engine light turns on. Great – I check the code and P0302 pops-up (and yes, I’ve had this code too!). I took it back to the dealer. I just got word back from the dealer and everything seems okay. The code popped-up during a cold start. I was told that if it were to happen again, they would adjust the valves on that side of the engine.
Now to my question(s) – with the problems my engine have had, that it was machined, and considering the age and mileage of my car, should I cut my losses and get rid of it? Trade it in? (I do not want another bent valve. I was out of a car for almost a month!) I’d prefer to keep my car for ten years plus, but will I be able to? Am I being unreasonable and/or irrational? I’m inclined to say that my particular car, and not Foresters in general, is kinda defective, but will listen to arguments stating otherwise. I’d really appreciate your opinions. Thanks for reading!
#2 of 44 Re: Valve/engine woes. Need advice. [heroine]
Oct 29, 2008 (5:51 am)
I have no mechanical expertise, so take my opinion with that in mind:
Sell it privately (don't trade it in) and buy another used Forester, maybe a 2006 or 2007.
#3 of 44 Re: Valve/engine woes. Need advice. [heroine]
Oct 29, 2008 (8:51 am)
A few things pop into mind. First, I think it is unlikely you had any bent valves, more likely burnt valves, usually the exhaust. Sending the head out to a machine shop to redo the valves is how you fix burnt valves. The valves and head are machined to make them like-new and the problem should go away. Valves only get bent through mechanical contact, in which case you have more serious problems.
When a head is done they should be doing the whole head and not just the cylinder in question. Since 2 and 4 are the same head they should have cleaned-up both cylinders. It would be ridiculous to do a valve job on 1 cylinder.
It is entirely possible that they set the valve clearances too tight and therefore not closing correctly. A compression test would show that, low compression in number 2.
Of course the codes you have been getting are for a misfire in cylinder 4 and now 2. There are many things that would give that code, ignition, fuel injector, and the appropriate wiring for each of those, but given that they found a compression problem in 4 the cause is most likely something involved with them working on the head, so tight valves are certainly first on the list. The other option is that something got damaged while they worked on it.
I would give them a chance to fix the problem. If they find it and it is simple like the valve adjustment, you should have a good chance of getting good life out of at least that half of the engine.
Of course that assumes they did the valve job correctly.
If they say nothing is wrong but you still aren't happy or comfortable then I would trade it in to them for another. If they think it is fine but you don't, then let them have it. I wouldn't stick another consumer with the problem. If someone buys it from them they will get a warranty, so it will have to be fixed correctly to their satisfaction.
Many times burnt valves can be caused by overly lean mixtures so you might want to consider where you buy your gas. I don't know what part of the country you are in but you might be getting too much alcohol content in your gas.
#4 of 44 Re: Valve/engine woes. Need advice. [bethanndee]
Oct 29, 2008 (1:05 pm)
bethanndee, thanks for the suggestion. I'd probably trade it in though. If it were serious, I wouldn't want to pass on to another owner....let the dealer handle it.
Thanks very much! I really appreciate it.
#5 of 44 Re: Valve/engine woes. Need advice. [bigfrank3]
Oct 29, 2008 (1:20 pm)
bigfrank3, wow! Thanks so much for the thorough reply. Here's my response:
I double-checked the work order (my receipt) and here's what it states:
"...bent exhaust valve. Valve guide damaged. ... Check for codes. P0302 & P0304 found. Engine riding rough. Perform compression test ... #4 0 PSI. Remove cylinder head for inspection. Found bent exhaust valve and valve guide had dropped down. Sublet cylinder head to machine shop for replacement of all valves and two valve guides. pressure test, and resurface. Replace valve seals and perform valve seating. Reinstall cylinder head and all other applicable components. Test drove vehicle, checked for leaks, none found, operation normal at this time..."
So all the above happened, and then P0302 popped up again. I was told that if the check engine appeared again, they'd probably have to readjust the valves - hence the purpose of my original post.
Just for the record, the most recent receipt regarding the recent misfire (P0302) states:
"...302 missfire #2 cylinder, set at cold startup, not a hard code. Possible low grade fuel. Cleared code."
Personally, I have no qualms about the dealership service dept - I would take my Subie back for maintenance, no problem. I think they do great work. Honestly, I think I just got a bad car.
So since my valve was bent through mechanical contact, what is your opinion? Trade it in?
Thanks so much for the reply. I really appreciate it!
#6 of 44 Re: Valve/engine woes. Need advice. [heroine]
Oct 29, 2008 (4:21 pm)
Well that IS unusual. The mechanical contact that causes bent valves is usually the valve hitting the piston. Sounds like the valve keeper let go and the valve dropped onto the piston while it was running. There could always be some fatigue that wouldn't necessarily show up with a visual inspection, and they don't indicate doing anything high-tech to inspect the head or the piston.
While it would most likely be ok I personally would trade it in, but wouldn't have the mind-set that it is junk because you will then spend too much money to trade. As I said before, if they think it is fine let them take it, and they can't low-ball you because it isn't fine. Tell them you have spent so much time there looking around that you have started thinking you want something newer.
#7 of 44 Re: Valve/engine woes. Need advice. [heroine]
Oct 30, 2008 (5:54 am)
On further thought, I think you are right that a trade in would be better than a private sale here. Usually, I think of trade-in as a bad deal, but in this case, if the dealer insists that they have fixed it correctly, then they should be paying full trade in value; if you sell it privately, the buyer will be paying less than regular private party value, due to the car's history. So the trade in value is probably higher in this case.
Of course, the dealer will then tempt you to buy a brand new shiny one!
#8 of 44 Re: Valve/engine woes. Need advice. [bigfrank3]
Nov 07, 2008 (5:28 am)
"... 2004 Forester 2.5X currently has around 68,000 miles... On a few occasions (before 60,000 miles), usually going uphill, my car would feel like it was about to stall, but the dealership found no problems. A little over a month ago, my car sputtered again, this time on a freeway. I pulled over before it stalled. It had to be towed. The code that showed up was a P0304. What the dealership found, via a compression test, was that an exhaust valve in the #4 cylinder was bent..."
"... The mechanical contact that causes bent valves is usually the valve hitting the piston. Sounds like the valve keeper let go and the valve dropped onto the piston while it was running. There could always be some fatigue that wouldn't necessarily show up with a visual inspection, and they don't indicate doing anything high-tech to inspect the head or the piston..."
It doe not sound like the keeper suddenly came loose and suddenly dropped the valve onto the piston to make a mechanical contact. This would have caused more extensive damage than reported. The owner says the car ran for 8,000 miles with the problem. More likely the guide worked loose in the head and dropped down a bit as the shop reported. The valve would have been poorly guided and supported, causing a slight bend. As the guide dropped lower, the valve would also eventually be unable to close completely, causing compression gradually falling to zero. It is fortunate that the valve did not break or the guide fall completely out, as the piston and cylinder would have suffered severe damage with particles going throughout the engine. As it was, any particles from an exhaust guide working loose in the head would have been blown outward to accumulate as a residue in the valve cover.
#9 of 44 Re: Valve/engine woes. Need advice. [aatherton]
Nov 07, 2008 (9:49 am)
Allan, that is certainly plausible, except that I have never found valves to be fragile and bend unless they are struck. Perhaps the most likely cause is somewhere between the 2 scenarios. If the valve was in fact still "kept" but the entire assembly moved lower in the head, then maybe the valve still got kissed by the piston. There is not a lot of clearance there. I have never found a valve to get bent just because it was allowed to "wobble" a bit because of a bad guide, unless it got hit by the piston.
Given that there were also codes for cylinder number 2 along the way I did not make the assumption that this was the exact problem that appeared before the 60K mark.
Too bad you and I weren't there to tear it down.
#10 of 44 Re: Valve/engine woes. Need advice. [bigfrank3]
Mar 25, 2009 (8:35 am)
i just wanted to say thanks for all the comments and give a quick update on the thread. four months on (march 2009), the car seems fine. a final valve adjustment was made back in november 2008. i've driven about 6000 miles since then and no problems.
thanks again for all your insight.