I removed the under-engine plastic shield to change my axles, and left it off for the test driving.

I had noticed incredibly high underhood temperatures of the S60 here in Texas, but the dealer said that it was required for mainly noise reduction, and it contributes to fuel economy by keeping the airflow stable under the car, though at only 23mpg for my T5, I can't believe it helps economy meaningfully.

When I got home from the drive, I opened the hood and was amazed that no wave of hot air greeted me as before, and I could easily touch certain metal components that I couldn't get near when the cover had been installed.

It would seem lower underhood temps would increase the life of especially rubber components like belts and hoses.

Is there any downside to leaving it off? Does its absence effect airflow for proper road cooling in a negative way? I really don't see how it helps with water splashing up or anything like that.

Back when my daughter bought her (new) '07 S60 2.5T, and having read (in IPD's FWD catalog that these cars have a vulnerably-placed oil sump (compared to a higher underside 240 that I was used to), I thought that I would buy her a metal "skid plate" to protect the underside of the engine sump and transmission from things like hitting a cinder block or other road debris.

Wanting something better than IPD's aluminum shield, I found that Volvo actually sells a steel protective plate. It's p/n is 9451784-4.

But I also discovered that with the part comes a warning -- paraphrasing (it's been a few years since I looked into this, so I'm going by an almost retired person's memory :-), it cautioned that this plate should not be installed in areas where there are high temperatures, as this part increases underhood temperature.

It's seem obvious, then, that any shield under the car will interfere with air flow through the engine compartment. The 240s' "splash pan", extending from the radiator back to the crossmember under the front of the engine, does protect from road splash and is useful in this regard, but it's easy to see that a farther back plate would prevent air from freely flowing over the engine compartment and exiting under the car. Of course, the relatively simple engine compartment of 240s hardly compares to the astonishly cramped compartment of my daughter's S60, and virtually all other contemporary cars I've seen (a do-it-yourselfer's nightmare, but that's another story :-).

The shield allows for better airflow through the radiator and keeps the armadillos from bouncing up into the steering gear :>)

The shield also tends to fall off when going up too close to concrete dividers or curbs in parking lots. Last I heard, the shield for my V70 is about $70 at the dealer.

Klaus
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Always willing to listen, just not able to take direction.

Ok, how much technical detail do you want on this? I'm going to try and be as simple as I can, and leave out all math, and as much theory as possible. If you want a detailed description of all this stuff, I'd be glad to give it. I just don't want to confuse the crap outta you...

Anyway, The bottom shield will slow down airflow significantly in the engine bay to under the car. Taking it off will allow more air to get under the car and you'll have a cooler engine. This does come at a trade off though. The airflow causes turbulence on the underside of the car, which will effect economy. If I had to put a figure on it I'd guess a 1% difference, not that noticeable, right? However, the other thing it screws with is your handling. Have you ever heard of ground effects? Well, the bottom of the car being more or less 'flat and solid' is wonderful for creating (and holding) a low pressure zone under the car, so the higher pressure above the car 'pushes' the car down on the ground. Removing the shield will let air be 'sucked' under the car, which lowers that pressure, and removes some of the down force holding you on the road. Now before you fret, its not going to be a significant amount at normal operating speeds, however when you get the car 100+ mph it can be a significant loss. The shield also blocks things from coming up and hitting the engine or any components within. Probably not a huge amount of damage if you stick to paved roads, but if you live out in the country with plenty of gravel roads it'd be best to put it back on..


OK to summarize:

Pros
- Better engine cooling
- Not have to put it back on


Cons
-Slight loss in fuel economy
-Slight loss in down force
-Have to re-attach the shield
-Higher risk of object striking components
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If you're not driving it "like its stolen," are you really driving?

Thanks.

The points you make are all good ones.

Given their implications, I think for me the operative points are

HEAT: I live in Texas where summertime temps reach 100+ many, many days, and the underhood temps I noticed this year in the S60 were incredible compared to my other vehicles.
As an aside, the valve cover has noticeable sludge (despite my nephew having used synthetic almost the whole 103k miles on the car, assuming the shop actually USED synthetic vs. just charging for it). Heat probably increases deposits.

DOWNFORCE due to smooth airflow: I rarely, if even even touch, 70mph, even on Interstates, so I think it's safe to say that I'd be OK there. I am not quite an old fart yet, but after a nearly 40 year career flying supersonic jet aircraft, I am somehow satisfied to drive near the limit, even with my Backdraft Cobra. I guess I just got it outta' my system. I know, it's sad and pathetic, but hey, it takes all types...

As for a 1% or so fuel economy hit, the T5 I have (sadly) gets such mediocre mileage it probably wouldn't be noticed. I'd complain about the mileage, but everyone says the N.A. cars get 28-32mpg, but the 23mpg I get w/ the T5 is near the top of the expected mileage for the turbo car.

FOD (Foreign Object Damage): Valid. I once ran over an alternator that had fallen off the car ahead of me. Fortunately, it did no damage to my Rabbit Diesel (phew!) but it sure COULD have. The plastic shield is pretty heavy, and could probably prevent a solid blow that could crack an oil pan or transaxle case.

All-in-all, I think the extreme engine heat situation, at least in the summer, is the overarching concern in my case for now.

Thanks for the good considerations,
Bob

If you're changing your coolant (as you should be) and using OEM thermostats (as you should be) you shouldn't have any problems with heat. Your underhood temps will probably be high with this car in this climate though. Did you say yours was the 5cyl or 6cyl? The sixes are known to be very hot.

Be sure to try to keep your rad clean too.

IIRC the splash guard pan thing you are referring to should actually HELP with engine cooling by directing more air through the rad.

AutoRX seems to be the best remedy for engine sludge, but a good oil will clean it up slowly over time (years). If you were having a shop do 'synthetic' oil changes they were almost certainly not using 'real' synthetic. In some parts of the world there are stricter rules about what is allowed to be called a synthetic, but in NA it's pretty crappy. Most 'synthetics' - even most viscosities of Mobil 1 - have very little real synthetic oil in them, and are actually highly processed petroleum oils. And as such they are HIGHLY overpriced.

As I mentioned in a previous post on another thread I am going to be switching to a diesel oil to benefit from the higher detergent, TBN, ZDDP levels, and the associated cleaning and protection that come with them. Diesel oils fit the 'turbo' bill quite nicely, and the quality oils are much less expensive.

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1998 V70 AWD->FWD Turbo 200k+

I think the high underhood temps have manifested themselves by the fact that every motor mount, every hose, all of the coil packs, the alternator-virtually ANYTHING even remotely heat sensitive plastic or rubber has been replaced on this car at 100k or under.

As for the airflow through the radiator, I was wondering about that, but I really don't see much area for the air to exit the engine compartment (providing a low pressure area) w/ the cover in place. There are a couple of very small louvers at the rear of it, but otherwise not much. Maybe around the axles? Of course, this hot air exit could explain why both inner CV joint boots were shot (I just replaced both axles at 103k-one boot was totally shot, the other cracked); typically it's the outer boots in my experience that go first due to the flex with steering (when I lived in Alaska, if you left the wheels turned in your Subaru at 30 below when you parked, you could plan on tearing a boot almost instantaneously when you drove away).

We'll see. I have never seen a car (other than a Range Rover) that piled up $16,000+ in underhood repair receipts in under 100,000mi as this S60 did (my nephew, the previous owner). They loved the car, but between the $28k in depreciation, the repair bills (I didn't mention 3 cracked and bent 17" wheels from Dallas road potholes), the expensive tires ($300 ea from dealer every 30k), they just could no longer justify the expense.

I can't say heat contributed, but anytime I opened the hood during their ownership it seemed incredible, but life's an experiment.

As for synthetic, the first 50k they had Volvo use "Volvo" branded synthetic (I don't know who made it for Volvo), and since then it's been Valvoline I believe. They paid $60-$75 per oil change, so I'd like to think they got the better stuff.

I use diesel oil in my other vehicles that have flat tappets (I have two diesel among my 8 cars), but I think I will use the few cases of Amsoil 10-30 synthetic I have left over from a twin-turbo Nissan I once had in the S60.

I used WalMart supposedly "full" synthetic in my 965 and the valve cover stayed like new the entire time I owned it. The 5cyl S60 (basically same engine, of course) looks like peanut butter in there, and I am waiting for something to clog an oil passage, so a VERY slow cleanout would be safer.

Yep, the guard will allow a bit more air to the face of the radiator, but it has nowhere to go in the engine. This leads to more air being splashed over the sides and top of the car as opposed to through the radiator. Taking it off will help extend the life of your other components (those not designed to sit in a 200 degree oven..., CV's, mounts, timing belt, ect.)). 16k is a lot for repairs thus far, and 30k outta your tires is also really crappy. I wonder if there was more to his driving then getting from here to there.. I know the 6-cyls are bad at being hot, but most of the 5's are pretty good. Then again, I'm not in texas..

If I were you, I'd leave it off. Most of the impacts you'll get underside is from rocks bouncing from either cars coming the opposite way, or those in front of you. There is the occasional tire/debris on the road to watch out for too. The easiest way to get around it is just defensive driving. Leave lots of room between yourself and the car in front of you.

As far as the handling part goes, if you haven't really used the car before (like taking butterfly off-ramps at highway speeds...) you won't notice it. Its a small change between the two, but it'll be consistent. Its more of a problem if you were taking the car out on track days, took it off, and kept pushing the car to previous limits.

As to economy, if it drops you 1% (which I think is high) it'd be ~.2mpg difference. Not that noticeable.
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If you're not driving it "like its stolen," are you really driving?

Taking it off will help extend the life of your other components (those not designed to sit in a 200 degree oven..., CV's, mounts, timing belt, ect.)). 16k is a lot for repairs thus far, and 30k outta your tires is also really crappy. I wonder if there was more to his driving then getting from here to there.. I know the 6-cyls are bad at being hot, but most of the 5's are pretty good. Then again, I'm not in texas..
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Yep-I agree and think it partly explains all (or part of) the replacements I mentioned.

Yes, I think my nephew paid WAY too much for repairs. The dealer charged $1600 for the timing belt change alone, and they didn't even replace the water pump (I wish they had), because they wanted another $255 for that.

They also charged $1000 to replace the driver's side window and regulator, and wanted $600 just for the glass for the left rear door glass (it's laminated glass and the outer pane cracked), so they declined to replace it as well.

As one example, the upper engine torque mount (on the valve cover to the firewall) dried and cracked at about 30k miles, the dealer wanted $450 for, and he bought the part from FCP Groton for $60 and it took 15 min for me to replace. They wanted $600 for front brakes (the rotors were fine-no gouging or warpage, so we just installed pads for $60). The dealer quoted $1500 for an alternator (he had it done for $600 by an independent shop).

He always bought the softest tire compound tires for best handling, which explains the 30k lifespan of them. He drives hard, but this was his wife's car, and she put 95% of the miles on the car, and she drives very easily as her two kids are always inside, if for no other reason.

I think that a lot of things on the car have gone bad (including the trans at 60k miles), too soon, but the dealer charges were way high in my estimation. I shouldn't complain, though, since he sold me the car in disgust for $3000 (that's what Car Max offered him)! With new axles as of last night, it's a different (and most enjoyable) car! Last chore is to eliminate the drift-to-the-left it still has.

Overall, his unhappy experience (He says he'd NEVER buy another Volvo) were due to over zealous billing, and I have to believe all of the underhood failures were somewhat heat related. I've owned Volvos for decades, and based on his single experience, I can't blame him. It's really sad-maybe a less "hungry" dealer network would have resulted in more cars sold, and a company STILL in "Western" hands, rather than a Chinese company.

I don't know how much the turbo adds to underhood temps on the 5 cyl, but trust me, opening the hood was like putting your face into your oven. With the shield removed, it's not, and I figured w/ the open bottom, it might actually FEEL hotter since you now have all that convection air up from the open bottom, but it's not. I should take some measurements of specific items w/ my infrared non-contact thermometer for comparison.

Honestly, Volvo trying to compete with BMW for luxury dollars is what screwed them in the Ford years. The 240 and back are very high quality, very safe (for their time), very well made cars. The 850 was also quite high on the traditional Volvo criteria, but they also decided to go with the 'sporty' car segment. They did alright, and have since been trying to improve their share in non-traditional Volvo market. However, this cost them because they're losing ground in what was once Volvo's category. Volvo's average age of retirement is 14+ years second only to Mercedes, but its going down quite quickly with the '00s factoring in.

I think the Chinese ownership (which I understand still leaves Volvo 'in charge') won't necessarily be a bad thing. I just want them to go back to what made them a success.


BTW, tell him that the dealer was taking him for all he's worth, and that isn't normal of a volvo. Those repair costs are insane. 1500 on an alternator? Perhaps I'm missing something but even at the $500 dealer price, 1000 in labor for an hour job? WHAT???
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If you're not driving it "like its stolen," are you really driving?

I think the Chinese ownership (which I understand still leaves Volvo 'in charge') won't necessarily be a bad thing. I just want them to go back to what made them a success.


BTW, tell him that the dealer was taking him for all he's worth, and that isn't normal of a volvo. Those repair costs are insane. 1500 on an alternator? Perhaps I'm missing something but even at the $500 dealer price, 1000 in labor for an hour job? WHAT???
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I HOPE the Chinese let Volvo do its thing, but if I owned Volvo, it would be hard not to stir the pot a bit.

I talked myself hoarse for the 8 years he owned the S60 (which is why I did some of the work on it for him) about price gouging, but they just felt more comfortable at the dealer. The $1600 timing belt and $1000 driver's window were the last straws, I think.

They had an Independent Volvo Shop for a while who was almost as bad as the dealer (why not-he had the field to himself), but had a real attitude. He is Swedish and acted like he's a Volvo God (reminded me of the "Soup Nazi" if you ever watched "Seinfeld" on TV). He accepted or turned away work depending upon his mood, and if the customer winced at the price.

The new-alternator-only price from the dealer was just under $900 (it's the one w/ the free-wheeling clutch on it) plus $600 labor, from the Independent would have been about $1100 installed (but he said he wasn't interested in doing it then), and from a non-foreign specialty shop I suggested about $600 or so installed (Bosch reman alternator) as I remember w/ out looking up the receipt.

I LOVED my 240s, my 740, and my 965 especially. Maybe the S60 will grow on me if it behaves itself, though I'd have prefered a RWD, or at least a "brick" 850/S or V70 for the interior spaciousness.

I figured $3000 for a near-mint car with all those replaced parts and a family history was worth a shot, though. I know the 2001 model had transmission problems, but hopefully when it was remanufactured two years ago the shop did whatever mods would enable it to last like the newer ones.

Bob

Hmm, I was under the impression that the transmission wasn't bad on the FWD's. I always thought the 01-03 AWD's had the problems..

I wouldn't flush based on that mileage unless the color became dark brown that quick. Definitely get synthetic in there if its not already though.

I think I'd like to see a new RWD from them.
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If you're not driving it "like its stolen," are you really driving?

Actually MANY of the FWD models have trans problems, and the 2001 5sp seem to be especially susceptible. I think the real problem is a combination of fluid capability and software programming, because the exact same Aisin transmission is found in many other cars (GM, Toyota, etc) with little to no problems reported. Both of those manufacturers use their own control software which may/may not be easier on the trans than Volvo's software. Also both of those manufacturers specify a fluid change interval in the maintenance schedule, while Volvo doesn't. I have no idea how the various transmission fluid cooling systems compare either.

There is actually not a huge difference between the AWD and FWD versions of these transmissions either from what I can tell. They are different but it's internal gearing/differential stuff. And although I have no real evidence of this I can't recall the reports of AWD transmission problems being nearly as high as the reports from the FWD cars, but there are a lot more FWD cars out there too...

Also Volvo's OEM fluids are not synthetic, but switching to a synthetic fluid will do some serious good for the trans. Synthetic gear lubes and hydraulic fluids are better in every way.


The 4sp takes a DEX-III compatible fluid, the 5sp takes 3309/Toyota-IV compatible fluid. Both are available in synthetic form (regular 3309 is not synthetic).

The AWDs do seem to have some problems with bevel gears (angle gear/transfer case/etc) and that fluid should also be changed on a regular interval - Fully synthetic 75W-90 GL-5.

Also wrt your comment re colour/smell - I have yet to find a 'modern' (P1+) Volvo that didn't have burnt trans fluid. I don't know anything about what trans is in this guy's car, but he said he's just over 100k miles which is where I would expect the OEM fluid to start giving up...

An AutoRX treatment would be a good choice to help slowly and safely clean it out as well.
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1998 V70 AWD->FWD Turbo 200k+

I wouldn't count on any 'mods' - get your trans fluid on a 25k mile flush schedule and start using fully synthetic fluid to keep your trans in good shape.
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1998 V70 AWD->FWD Turbo 200k+