The 120 has an alu sump with the drain plug 3/4 of the way forward on the left side. I.e. Not the black steel sump.
I filled 9L incl the filter ((for an early 140). This gave a low reading on the stick, which is a bit unclear with 3 dents and text further up (min max). At the lowest of the 3 indentations.
Oil pressure readings are as prior to oil change.
Depends on whether you have the early (relatively) flat bottom (120 only), or the later (obviously) stepped bottom (same as most Mark VIIs).
and…check the dimensions, marks on the dipstick itself to find which dipstick you have…is it the correct one…for the sump/application. There were several…easily switched over the years. It is in the archives I am sure…but I will look for my notes on dipsticks. Nick
The sump is flat, rectangular without cooling fins like the E-type
These are the two sumps used on XK120.
Flat bottom above (i.e. relatively flat in the mid section)
Stepped bottom below
This from archives and open to scrutiny: Various dipsticks (indicating the engine oil level in the sump) were used over the period of 1948 to 1961 for the XK’s. Changes were the shape and length of the dipstick and also the actual minimum and maximum oil level marks did not remain the same. There were in total 6 versions, and over the years, a prior owner/mechanic could have replaced a missing or damaged original dipstick with any other, without realizing the differences. It is worthwhile to have a look.
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The XK 120 started with dipstick C2348 from its introduction in 1948.
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The first change was made in January 1950 (C2348/1) caused by an increased oil quantity: oil level was increased by ⅝” (or 16 mm). It was recommended to cut new marks in the C2348 dipstick of already supplied XK 120 engines.
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With the introduction of the XK 140 a new dipstick was used (C7486) which had a minor difference in oil level but was otherwise identical to the previous version.
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A new dipstick was supplied from engine number G1908 onwards (coded C8781) after an oil pump modification. The maximum oil level was lowered by 3/8”( or 10 mm). This version had a much longer handle and it was continued over the rest of the production of XK 140 (except LHD FHC: see under 5) and the later 3.4 and 3.8 XK 150s (see early exceptions under 6).
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The XK 140 in LHD FHC execution had a special dipstick coded C10365 with a much shorter handle. This was because of the restricted space of the FHC body version in general and the LHD steering column in the way more in particular.
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Early 3.4 (V 1001 – V5059) and 3.4S engines (VS 1001 to VS 1303) had a different dipstick coded C13277. The maximum oil level had been slightly raised (about 1/4 “or 6 mm) and the handle was shorter in comparison to the later C8781 version.
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XK120 SB 59, Jan 1950, dipstick that was 221mm ( 8 11/16 inch (45/64 in) from under stop collar to full, to be changed now by dealers to cut a new notch 16mm (5/8 in) above the prior single full mark notch, so that from the new higher notch to felt under the collar is 205mm. Now 8 1/16 inch per the SB, (8 5/64 inch to be exact, but say 8 1/16 inch ) This increases the oil capacity, now to the new upper full notch to be 34.8 US pints total engine including oil filter and oilways, Sump capacity alone is 28.8, thus the math says 5 pints are contained within the oil filter and engine itself. This change made due to cornering and reported drops in oil pressure. So, some early XKs would, if dipstick was modified per this SB, have the two dipstick marks, and if not modified, only one, which would still be 8 11/16 inch(221mm) under collar to notch. First dipstick C2348
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The factory must have at some point changed the dipstick, with the higher full mark. Is this listed in production changes or a SB? It is X2348/1
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My March 53 XK120 has a chrome dipstick, with two notches. The total under collar to tip is 257mm, (about 10 1/8 yo 10 14/ in) from collar to full 205mm, (8 1/16); and from under collar to the lower add notch is 83/4 221mm. From the tip at bottom of stick tip to lower mark is 1 9/16 (38mm) and from tip to upper full is 2 ÂĽ in (54mm. ) Lower notch to upper Âľ or say, 5/8in. It is 2 qts, low mark to full mark.
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: Original first factory spec for the flat sump is 28 US pts, dry with engine total 34 US pts., then per SB59 with a new higher by 5/8 inch full mark on the dipstick, flat sump 28.8. With the stepped sump the sump is 25 US pts 12.5 qts sump only…plus oil filter amount, engine 28 US pts.)
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Note SB 97 page 3, (Nov 1951) now the Mark 7 Stepped sump is on the xk120, engine W3593-3596, and W3635 onward, with new sump (sump only) capacity being 25 US pt, and including oil within /filter assy & Engine 28 USA pt. No mention here of the dipstick to be used.
Nick
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Great info Nick. I will print this and put it my garage. But my stick has 3 notches and Min Max stamped on the stick. But not easy to understand what is what.
The sump is the 3rd one, with the oil level aperture blanked off with a covee and screws.
And this 1953 120 has the upper one, with a relatively flat bottom. 19 pints is exactly 9L which I used, and landed on the upper notch, of 3!!
I willcheck again tomorrow.
Ah, yes. I should have said there were four sumps, though the last three are really the same one, with sender, with blanking plate, and without holes for sender nor screws.
Here is an original XK120/MarkVII C.2348/1 dipstick with just two notches, and no other markings, from an engine with a stepped sump.
Hi Nick, the dipstick on my Sept 1950 XK 120 OTS LHD is not like any of the ones illustrated. It is 14 1/2 inches long.
Two notches, 1st is 3 inches from bottom, 2nd is 3 5/8 inches from bottom. The handle part from flat part of stop to the end is 2 7/8 inches. I am pretty sure it is original. The car takes 15 or 16 quarts (from memory).
David,
I’m “responsible” for the survey of dipsticks as shown by Nick. Like Nick stated: the survey is open to scrutiny and I would love to receive corrections to further improve the survey… (Thanks Rob for the photo of C.2348/1 which is apparently slightly different from what I had received. I will correct this).
But the dimensions David provides are so far from what is normally there on XKs, that I really doubt whether this is an original Jaguar XK oil dipstick.
David, you refer to a distance of 3 inches from the bottom to the lower mark where the first mark is normally between 1 and 1.5 inch for XK 120s. This will lead to a very high oil level!!! The distance to the next mark (5/8 inch) as well as the handle length (2 7/8 inch) are both correct again. Are you sure that you didn’t read 3 cm instead of 3 inches? Also, the most important dimension is the one from “underside stop” to the “top mark” and should be slightly over 8 inch. This is the real indication of the oil level at max.
You refer to 15 to 16 quarts of oil, but I gues this should be closer to 12.5 to 14 for a stepped sump type, so another indication that your marks are incorrect.
Peder,
Your dipstick looks like a genuine XK 120 version but only the two marks at the top are the correct ones for an XK 120. Forget the lowest mark and the indications for MAX and MIN as they are incorrect (don’t know where the third mark comes from but the stamping MAX / MIN is clearly done later).
Bob K.
Sorry Bob, but I have to stick with what I stated. I have owned the car for 44 years and have done most of the work, including most of the restoration work on the car in 1993-4. About four years ago I took it to get check out by the only Jag mechanic I trust and he also thought what I told him about how much oil to put in was off. He stopped at 15 quarts and I am pretty sure I had to put in another quart when I got home to bring it up to the proper level. Here is a picture of the sump and dipstick. (Please ignore how dirty it is underneath, it is going back to him to take care of leaks since I can’t get under the car anymore)
Sorry Bob, but I have to stick with what I stated. I have owned the car for 44 years and have done most of the work, including most of the restoration work on the car in 1993-4. About four years ago I took it to get check out by the only Jag mechanic I trust and he also thought what I told him about how much oil to put in was off. He stopped at 15 quarts and I am pretty sure I had to put in another quart when I got home to bring it up to the proper level. Here is a picture of the sump and dipstick. (Please ignore how dirty it is underneath, it is going back to him to take care of leaks since I can’t get under the car anymore)
14(ish) quarts sounds correct: I used to do tons of oil changes on 120s, and in doing so, had two five-quart oil pitchers, to add the oil, then topped that with something like 2-4 qts.
It was then I also learned to replace the drain plug, before putting in the oil…
My take on engine oil capacities have changed over the years. I used to fill all my Jaguars and BMW coupes to the upper mark on the sticks. But I now settle for half way, in order to reduce the pressure in the crank case ventilation system. I have found that the Jaguars tend to leak a bit less, esp at the famous rear crank seal, although the big difference comes with a modern lower half seal, against the sump cut out, combined with German WĂĽrth RTV sealant.
As long as I have normal oil pressure, I am comfortable.
Peder
Absolutely: I always drove Tweety, and any other of the family and customer Jags, at or close to the bottom mark/ crosshatching.
Davidn
Thanks for the photo: this really solved the problem. All measurements are correct (in particular the distance from underside stop to top mark: just over 8 inch) for a standard C.2348/1, apart from the length of metal below the bottom mark. which I read is about 1 inch too long. But this will not influence your oil level reading! Therefore the total length of the dipstick is also over 14 inch where about 13 inch is correct for the standard C.2348/1.
I don’t know what is beneath the dipstick and wonder whether there is anything that a too long dipstick could touch.I would cut off the extra one inch on the bottom of the dipstick and yours will be exactly like the one Rob Reilly showed.
Bob K.
Thanks, I think I will just leave it the way it has been for the last 69 years and the way it came. It drops done straight without touching anything.
Is it my imagination or am I missing something, doesn’t, the sump look a little different than the others pictured? Noticing the bump out and the ridges towards the front of the pan. Could be the space for the extra oil the car takes.