wind77west 13 #1 Posted July 16 I recently purchase a Wheelhorse/Toro 518xi (1998, 500hrs) with a 52” mower deck. Here my question. The first time I used it after about an hour of cutting (87F degrees outside) I noticed the oil temperature gauge getting close to the hot mark on the gauge but I was done with my cutting. I did some reading on this mower and high engine temperature and it gave me the following information, dirty engine, running lean, low oil or load. The temperature reading on the oil filter is around 274F degrees the oil meter was about ¼” from high temperature. Ran the mower with the left side tractor panel off, that seemed to help a little. It went to within ¼ of the high temp and stayed there I cut for approx. 1.5 hrs. I have done the following to see if I could help the high temp issues. Changed Oil (Mobil 1 10w-30) Cleaned engine cooling fins/oil filter cooling fins. Installed Kohler cover access plates and cleaned fins again. What I could see of the cooling fins and the blower fan appear fairly clean, blowing them out with an air compressor I could not see much if any dirt coming out. I have not run the tractor long since I installed the access plates, but was disappointed that the cooling fins looked clean. I would appreciate any input of what the problem may be. I have not found any information on the temperature sending unit or the temperature gauge itself. What is the actual temperature when the gauge hits the hot mark? Share this post Link to post Share on other sites
953 nut 55,449 #2 Posted July 16 It seems you have done all the right things to ensure cooling air flow for the engine. Operating in the normal temperature range whether high or low shouldn't be a problem. Share this post Link to post Share on other sites
JoeM 7,874 #3 Posted July 16 11 hours ago, wind77west said: What is the actual temperature when the gauge hits the hot mark? Not sure. I have 4 xi machines running. The larger deck 60" will make the gauge run right up on the high end before red. The others ran with 48" decks run similar to your readings. I use Rotella T-6 full synthetic oil, 5-40. The cooling air has a path designed to effectively cool the engine on these machines. Make sure the foam seal is in good condition between the engine and fire wall. This keep the hot air from re-circulating from the engine compartment through the cooling fan. Another thing is the side panels actually direct air flow. The cooling air comes through the shroud across the heads and out the front. Probably not the best idea leaving those off. (it allows the sending unit and filter to be cooler but what we want is cooler heads and sump.) Make sure the cooling fins on the heads are clean. I use a small 1/8 brake tube rigged up to a blow guns so I can keep those clean. Also, keeping the sump air cleaned too. Along the bottom of the oil pan. As an example. I checked the temps on the exhaust. The pipes coming out of the heads run right around 700. The muffler shield will be 200 itself. No secret air cooled engines run hot. 274 is on the upper end (and not a deal breaker for synthetics) but that is the reason we change oil so frequently in air cooled engines. A tell tail sign is when the oil starts to blacken. Sounds like your on it! 1 Share this post Link to post Share on other sites
Wild Bill 633 847 #4 Posted July 16 According to the attached, petroleum oils can withstand 450 degF, whereas synthetics can withstand 500 degF. I have (2) Commands in Simplicity Sovereigns, both with oil coolers and 140-300 degF oil temperature gauges. The normal operating oil temperature is 210 degF. On hot summer days while mowing, when the oil temperature reaches 225 degF, I shut down to allow the engine to cool down before finish mowing. You can also use the extra long oil filter, P/N 277233-S, which adds filter area and a small amount of oil capacity. Small Engine Syn Oil.pdf Share this post Link to post Share on other sites
peter lena 8,673 #5 Posted July 16 @wind77west oil needs to get hot , to properly work , flow , spread its function , protection . ironically just about any used anything I see , is totally neglected in that area , little to no oil on dipstick , always filthy black , transmissions , usually a watery , rusty mix , realy ? have a regular oil / lubrication track , that has been solid for me , like ROTELLA ,30 WT , with a 4 OZ RISLONE ZINC shot . engines are very smooth , quiet , zero smoke , also all my transmissions are clean / full with climbing gear oil , regularly go over every function for anything . my mower decks are quiet , smooth , no screaming pto drive , belt issues , every related bearing area , has a 550 drop point grease in it , love to clean out and RE GREASE any bearing , insuring quiet engagement , decks actually spin by hand at pto down belt area , also improved on every movement point on , PTO LEVER , many steps to eliminate drag / function . decks are clean / clear , no build up , hot oil soak , enhances that , change cutting pattern , drive speed , for better lawn look , minimize furrows / build up . only if you want to , pete Share this post Link to post Share on other sites
lynnmor 7,323 #6 Posted July 16 With the current heatwave at my house I wouldn't want to run 10W-30 now. There is more going on than just the oil being able to withstand the heat, there is the fact that oil being thinned to a real low viscosity can increase wear. 1 Share this post Link to post Share on other sites
Wild Bill 633 847 #7 Posted July 16 (edited) x Edited July 16 by Wild Bill 633 Share this post Link to post Share on other sites
RED-Z06 2,221 #8 Posted July 17 I like to see oil temps run 225ish, head temps around 255-265, you should be able to put a clamp on oil filter heat sink, or put on a filter adapter with an oil cooler built in. Share this post Link to post Share on other sites
Fordiesel69 263 #9 Posted July 17 Our 522xi goes into the red zone after 15 min of cutting with a 48in deck. The engine was an oily mess, so I cleaned it and took the tins off the get the cylinders and heads cleaned. Here is where I got to a dead end...........I have not been able to find anybody that would allow my to check the temps of their kohler / kaw air cooled engines. I wanted to check crankcase temp, cylinder head temp, and oil temp. This will allow me to deternine if I have a problem with the gauge / sender. Or if I have an issue with the engine. On your 518, I would take the time to peel the tins off while the engine is in place and wash up the engine just for the peace of mind. 1 Share this post Link to post Share on other sites
wind77west 13 #10 Posted July 17 On 7/16/2024 at 2:51 PM, Wild Bill 633 said: x Share this post Link to post Share on other sites
wind77west 13 #11 Posted July 17 Thanks for all the reply's and sorry I am so slow in getting back to you all. I had other problems pop up the rains/storms and my main computer died on me. Still working on that problem, using a small laptop for now. The foam at the air intake was in real bad shape so that was replaced I could really tell the difference in the air flow. I have not been able to see how much it helped because of the rain and cool weather (80's) not complaining. I will post again after a real test with some hot weather. The oil filter has a cooler on it and I cleaned it right after I noticed the heat problem and that did help some. Thanks again Share this post Link to post Share on other sites
JoeM 7,874 #12 Posted July 18 1 hour ago, wind77west said: I will post again after a real test with some hot weather Waiting for my burned up grass to recover and mow. I hope to remember to get some temps in and around the engine on the heads sump and oil filter. Share this post Link to post Share on other sites
Fordiesel69 263 #13 Posted July 19 Also I forgot to mention these need cleaned with a degreased like purple power simple green or other brand of chemical. It is the oil film on the aluminum that is the problem Share this post Link to post Share on other sites
JoeM 7,874 #14 Posted July 19 Mowed with a 522xi, 84 degrees outside, 48" deck, grass was not to high. Gauge was 2/3 the way in the green when temps were taken. It was pretty much there the entire time mowing. Temps oil filter 224 cooling fins on the side of the block also 224 sump 200 oil sending unit 197 exhaust coming out of the head 510 Share this post Link to post Share on other sites
wind77west 13 #15 Posted August 5 Finally getting life back to normal. I replaced the foam between the firewall and the engine shroud. The original was in real bad shape. I have used the tractor twice since then with out side temp on time in the uppers 80's mode for 1.5 hours and temp went 3/4 of the way in the green. The second mowing outside temp low to mid 90's again about 1.5 acres grass about 8-10" tall and up and down hills and the oil temp stayed 3/4 of the way in the green. It looks like the foam had the biggest positive effect on the oil temp. I would like to thank everyone again for there input and help. Share this post Link to post Share on other sites