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Oil Pressure Switch Replacement - 2010 Santa Fe 3.5L

172K views 116 replies 48 participants last post by  samwello2007  
#1 ·
Been lurking around here for a couple years and thought I would share some info and pics on replacing the oil pressure switch on my wife’s 2010 Santa Fe (3.5L). After 73K miles, this is our first mechanical issue of any kind with this car. The switch was not covered under the power train warranty, and after a $935 quote from our local Hyundai dealer, I decided I would make time to replace this $16 part.

The Symptoms
The oil pressure light started flickering, so we took it to the local dealer for a diagnostic. They said I had installed the o-ring on the oil filter cap incorrectly (I do the oil changes) and sent me on my way. A few days later, the oil pressure light was still coming on, and we found oil leaking on the garage floor. Oil was dripping from this area:

Image

(borrowed this pic from here...my stupid phone camera malfunctioned...but the leak looked exactly the same)

We took the car back to the dealer and the diagnosis was a bad oil pressure switch. They also wanted to replace the oil filter housing and the pressure switch housing (both unnecessary, in my opinion). The service guy explained that the $935 repair price was high because the switch and housing are buried under the intake manifold. Lots of stuff has to come off before everything can be replaced.

The reason the oil leaks where it does, is because oil from the leaky switch ends up pooling in the “valley” in the center of the cylinder block.

Image

There is a small hole in the valley, which drains the pooled oil. That’s what eventually ended up on the garage floor.

The Preparation
A couple years ago I bought a PDF version of a service manual for the Santa Fe. It’s about 1200 pages long and has step by step instructions for many things, including removal of the intake manifold. The illustrations (drawings) aren’t great, but the manual is a good reference and helped me prepare for the task.

I was also sort of prepared for a long day or two of work, based on my experiences with replacing lower intake manifold gaskets on a couple of GM 4.3L engines. Thankfully, the 3.5L engine on the Santa Fe involved a lot less time and work.

Tools needed (the ones I can remember, anyway):
· 10mm, 12mm and 13mm sockets
· 6mm Allen-head socket
· 24mm deep socket (with thinnest walls you can find)
· Phillips head screwdriver
· Small flat blade screwdriver to help unclip electrical connectors
· Standard pliers to remove hose clamps
· Needle nose pliers to help remove the clips that secure the wires
· Mechanic’s mirror to help locate a hidden 13mm bolt

The Task


The step-by-step instructions for removing the intake manifold are here. I won’t describe all the steps, and I didn’t take pictures for every step, but here are some highlights and advice:
  • Take lots of pictures. When it’s time to put everything back together, you won’t remember where everything went…trust me.
  • Before starting this project, fire up the engine and then pull out the fuel pump relay. Run the engine until it dies. This way, the intake manifold will be clear of fuel, and it won’t spill out when you remove the intake manifold. This also gets rid of some of the pressure in the fuel line, making it a little easier to unhook the line from the manifold. (Note: I didn't actually do this because I forgot about it until after I started disassembling stuff. But it always worked for GM's 4.3L V6 engines, and I'm assuming it works the same on the Santa Fe engine)
  • Plastic engine cover just pulls right off. Wasted about 5 minutes figuring that out.
  • There's a bracket behind the "surge tank" that has to be removed before that piece comes off. This 13mm bolt is hidden, and you probably won't find unless you have a mechanic's mirror. Here is the general location:
Image

  • Not everything listed in the manual needs to be disconnected or removed. Here’s short list of things I did not remove, which were instructed by the manual:
  1. Large wiring harness and plastic guide on front side of the engine. If you disconnect enough electrical connectors, this can be pushed aside.
    Image
  2. Did not touch the ignition coil connectors.
  3. During disassembly, I didn’t remove the injector delivery pipes on top of the lower intake manifold, but I did take these out for reassembly. They get in the way of the lower intake manifold bolts (6mm allen head bolts), and it worked better to torque the lower intake bolts without the pipes there. The pipes come out pretty easy, after removing the 5 bolts that hold attach them to the upper intake manifold (the injectors that are connected to the pipes just pop right out).
  4. Did not remove the metal radiator pipe that goes through the center of the “valley”. The pipe gets in the way of the oil pressure switch, but with a little creativity, I was able to find a combination of sockets and extensions that I could squeeze into the valley and get access to the switch.
Image

  • If you don’t have to remove the radiator pipe, I’m not sure if there’s any need to drain the coolant. Getting access to the drain plug on the radiator requires removal of the plastic underbody shield. It’s not difficult to remove the shield or drain the coolant, but it adds time. I only drained enough to get the coolant level below the intake manifold….may not have been necessary.
  • Probably goes without saying, but keeping things clean is pretty important. I tried to cover any holes that lead to things like fuel injectors and cylinders.
  • The new oil pressure switch came with pipe sealer already on the threads. If you happen to get one without sealer, the Internet is full of opinions on what kind of sealer to use (if any).
Overall, this was a much simpler job than my previous experience with intake manifolds, but it still took some time and patience. Working slowly, it was about a 5-hour job. Would be maybe half that if I had to do it again tomorrow.
 
#4 ·
Sadly .. just because it's not. If you look at Hyundai's 100K 'drivetrain' warranty, there are quite a LOT of things that are not covered. What is covered are the majority of the mechanical parts, but when it comes to anything with a wire attached, you won't find it there unless they're forced into it as an emissions related issue.
 
#10 ·
Had the same issue happen to me on vacation last week in Virginia. My 2011 Santa Fe has 67,000km on it. Thankfully I was able to get catch this before the oil level got too low. I was surprised there is no tone to the oil light flickering on! Searched the leak and found this post. I took it into Brown's Hyundai in Mannassus and got it replaced under warranty. They did a terrific job. Service manager chuckled that I had found the problem for them. Thanks for the post to help problem solve this. From all that I found on the internet, this should be a recall.
Hyundai Santa Fe 2010 Leaking - YouTube
 
#13 ·
I was told by a KIA dealer who also sells these used SF that the KIA new warranty is 100k for everything and not just the powertrain. I was surprised and assumed the SF was the same but did not look into it further since my warranty expired on time.


So I am guess they are different warranties for very similar vehicles.
 
#14 ·
Right... From their own site:

The Kia 10-year/100,000-mile warranty program* consists of:

  • 10-year/100,000-mile limited powertrain warranty
  • 5-year/60,000-mile limited basic warranty
  • 5-year/100,000-mile limited anti-perforation warranty
  • 5-year/60,000-mile roadside assistance plan

Essentially, the same as a Santa Fe. 5/60K bumper to bumper.
Good thing you weren't buying a car from him!
 
#17 ·
2010, Sante Fe 3.5 liter, just had to replace my oil pressure switch replaced at about 92000 km, oil indicator light began to come on when idling, procrastinated for a couple of days then began to see oil on driveway. Took to Dealer and they replaced for $379.00 Canadian taxes in. Agree that it appears that this should be a recall, due to it being a common problem. When I described my the symptoms dealer knew right away what it was..... Side note they also fixed a recall item; ECM Update - RPM Logic & ETC Motor Cleaning.
 
#19 ·
2010 Santa Fe with 147Km (92K miles) started to drip oil and intermittent oil light.
I found the instructions from this forum and installed the $18 part myself.
I took my time and it wasn't too bad. The one key step I didn't do is remove the cross over coolant pipe. Apparently this is a step required by the shop manuals. It made getting at the oil sensor difficult but I used a closed spanner (and switched directions each turn) because I could only loosen it 1 spanner tooth at a time!
Made sure to keep everything clean and stuffed rags into the intake ports.
It started first time and not leaks months later.

The dealer takes that pipe out so they can clean the oil out of the engine well. The parts guy at Hyundai said that if they don't clean out the oil it drips for a week or 2 after and the customer thinks the repair didn't work so they take that pipe out to clean out the oil. In my case I cleaned out what I could (using rags and a screwdriver to push it into the oil) but for a week after I still saw a bit of oil drip but that eventually stopped as I knew where it was coming from.

NOTE: I now wish I had replaced the spark plugs while I had the intake manifold off. I believe they are the original.
 
#20 ·
My wife's GLS exhibited the same symptoms. Was one month and 2 days out of warrantee with 99,000 km. Spoke with nearest dealer and was referred to dealer where we bought. That suggested contacting customer service to see about a goodwill. Head office check with both and refused as I do my own maintenance and seldom reply to their calls for service. A ten dollar part but few hours labour. Thanks aa21830 for the guidelines. Now I know would to change my plugs too.
 
#22 ·
if you can avoid pulling the fuel injectors... all the better. Apparent dealer says they do these all the time but never have to remove the fuel rail. Seems i cannot get them the seat properly and is literally pissing fuel. I am however getting really good at removing (lifting) the surge tank. Dealer says they have to order as no one needs to stock those LOL
 
#23 ·
Leave injectors-fuel rail attached to lower intake along with the fuel line attached,,, remove bolts for lower intake to head and lift the assembly off cylinder as a whole single assembly..lay it over by brake master
 
#24 · (Edited)
Update...leaking continues after multiple attempts. Coming from F.I. area closest to driver seat. Can confirm F.I. are lubed and seated properly. Replaced the O rings with felpro "seal kit" (even dealer does not stock as never needed). Nothing leaking when key to on/pressurizing fuel however starts to leak when running. Can now only surmise an issue with intake where it meets FI. that or its not torqued down properly. Will take another step backwards and redo that one...
 
#25 · (Edited)
Sorry for the tardy reply...After many attempts ..I eventually asked the misses to turn over the engine while the surge tank was not attached and stunned at what I found. Turned out the slight click i heard on initial reassembly was a hairline crack on the rear fuel rail where the bolt attaches (driver side). Hard to believe that as this bolt is shouldered by a metal sleeve and I in no means over torqued a 10mm on 1/4" ratchet. See photos. A replacement fuel rail was not an option either at $635 Canadian so I sourced one from a wrecker (complete with injectors) for $150 and 90 day warrantee :)
My interim solution was to sand the area, rub down with acetone, I then used a mini soldering iron to melt the area then wrapped with JB Weld...awesome stuff. Noticed the photo where I only used my mouth (pardon) and put minimal pressure on fuel rail to cause seeping gas through the crack (dark area). Thought it best to replace F.R.instead of repairing. BTW I used blue thread lock on the 10 mm bolts as an added precaution as i did not want a repeat performance.
All in all ... still turned out to be less expensive then going to the "stealership" seeing as my time is free. I may even drop off old rail (minus FI's) to the parts guy from the "nice" dealership as reminder that us "weekend warrior mechanix" can do comparable jobs...eventually


I had found nothing on the web with regards to this specific issue so believe this to be a first and thought better to advise... so hopefully no one else has to go through this. Who knows... this could be a weak point in all "plastic" fuels rails for Santa fe's or larger all Hyundai products :(


Thanks all
 

Attachments

#26 ·
I found this thread to be very helpful. Thanks very much to the OP and all that replied.

2012 Hyundai Santa Fe V6 AWD, 40k miles. Had the same leak as the OP. Looks like it might be a rear main seal leak, but the leaking oil up top under the intake manifold and dripping down the side of the engine was a dead giveaway. Made a major mess, drizzling oil at an alarming rate when the engine was hot and running. Oil light never came on, and I was careful to keep the oil up on the quick trip to the dealer. Leaked about a quart in 6 miles.

Dealer kept telling me that it was rear main seal, and then later that I had maybe overfilled the oil, ha. I kept telling them "it's probably the oil pressure switch," and even had a post-it in the car telling the mechanic such. Finally, they brought in a "Hyundai Expert Mechanic." He replaced the oil pressure switch and all is good to go. Took over a week, with a dye test and other bogus diagnosing, ha - you really don't need to clean the engine and then do a dye test when you can just clean and then look at the oil leak, but whatever.

Repair was fully covered under the 5/60 new car warranty. Rear main would have been fully covered under the 10/100 drivetrain warranty. My receipt says part is $12.70 and labor is only $26.70, so $40 total, but it was fully covered.

I think I might buy a spare switch and replace it myself next time.

FYI, and thanks very much again.
Jim
 
#28 · (Edited)
Oh God my 3.5l is leaking just like this - started probably yesterday Im guessing. Today, its really dumping. Parked it in the grass for now.

QUESTION for anyone who did this repair: COULD YOU TELL AHEAD OF TIME THAT THE OIL WAS POOLING IN THE VALLEY?

I took the cover off, and used a flashlight, and mine looks clean and dry from what I can see looking in between stuff.

Is the rear main seal covered if that is the cause? I just want to be able to tell before ripping into the intake, or take it to Hyundai - It just turned 99600miles, so if its rear main and covered, I will have it towed if needed. If its not covered, I have a local mechanic that will do the job cheaper than Hyundai (I'm not attempting a rear main by myself)

ANY help at all appreciated. (Im very mechanical, but like I said, Im not able to see any oil looking where I can see in the valley area.)
 
#29 ·
Rear main seal is not a fail item with our engines..

Common pee'ing oil leak we see is the oil pressure switch with the 3.5L

Edit your "DRIVES" to reflect what yr, Santa Fe, 3.5L 2WD or 4WD
 
#30 ·
Edited my info - 2010 SF 3.5l AWD.

So, just to clarify, After looking at everything I can find regarding this repair, it appears you can NOT see a pool of oil without pulling the intake. Is this correct? I have looked as much as I can without starting to rip into this and can see nothing oil wise with the intake and surge tank in place. Closest store that has the sensor is 30 miles away, so borrowing the wife's car tomorrow to go get the sensor, and hopefully rip it apart tomorrow night. Might as well do the plugs while I'm in there @ nearly 100K mi - any preference folks have for spark plugs?