TR4'er Posted June 4 Report Posted June 4 Below are photos of the rocker oil filler cap - highlighting the water condensation as recently noticed. The other 2 pics are of the radiator cap and its radiator cap fitting On the radiator fittings is a thick sludge - oil and water mix, as well as totally contaminating the radiator. The question for me is it just the cylinder head gasket gone, or is it another part of the engine/oil/water system that has failed to allow the oil to enter the radiator system. Can anyone with experience or knowledge of this problem advise me of the best course of action. I would prefer to deal with this myself. Thanks in advance for any options given. Rob. Quote
Hamish Posted June 4 Report Posted June 4 Head gasket or fig 8 liner seals on the bottom of the liners. is the sump full of water ? Quote
RogerH Posted June 4 Report Posted June 4 Hi Rob, how many miles do you travel in one go and how hot does the engine get. If you do plenty of short journeys then the moisture in the atmosphere that gets into the sump has not chance to burn off. A decent long journey may clear your problems. Roger Quote
Rob Salisbury Posted June 4 Report Posted June 4 Hi Rob, Have a look at the oil on the dipstick, if it's brown like the water in your rad then the fig 8 seals have gone, has the volume of the oil in the sump increased? .. that would be another clue, .... otherwise, from the oil in your rad, it'll be a head gasket problem. Cheers Rob Quote
trchris Posted June 4 Report Posted June 4 Hi Rob Agree with Rob if the oil on the dip stick looks good it’s likely the head gasket Chris Quote
Steve-B Posted June 4 Report Posted June 4 (edited) Roll up a bit of kitchen roll into a cigar shaped rod, stick into open radiator. If it’s not blue/coolant coloured or dark thats not good so you’ve got to drain the oil and let it sit. Water obviously lighter than oil so if any appears more investigation needed. Edited June 4 by Steve-B Quote
TR4'er Posted June 4 Author Report Posted June 4 4 hours ago, RogerH said: Hi Rob, how many miles do you travel in one go and how hot does the engine get. If you do plenty of short journeys then the moisture in the atmosphere that gets into the sump has not chance to burn off. A decent long journey may clear your problems. Roger Hi Roger, thanks for your coments - my TR4 - 1964, is used mainly for long journeys - 250mls per journey then return - 500mls, - at least 4 times per month, and over those runs, sits at just hotter than mid point on the guage. Any further comment would be appreciated. Thx Rob. Quote
TR4'er Posted June 4 Author Report Posted June 4 4 hours ago, Hamish said: Head gasket or fig 8 liner seals on the bottom of the liners. is the sump full of water ? Hi Hamish, the oil in the sump looks as normal with no discernible chnge in level. Thanks for being so prompt. Rob. Quote
TR4'er Posted June 4 Author Report Posted June 4 (edited) 4 hours ago, Rob Salisbury said: Hi Rob, Have a look at the oil on the dipstick, if it's brown like the water in your rad then the fig 8 seals have gone, has the volume of the oil in the sump increased? .. that would be another clue, .... otherwise, from the oil in your rad, it'll be a head gasket problem. Cheers Rob Hi Rob, oil in the sump is normal colour and no discernible change in level. Yes. Probably the Head Gasket. Thx again. Edited June 4 by TR4'er Quote
TR4'er Posted June 4 Author Report Posted June 4 2 hours ago, Steve-B said: Roll up a bit of kitchen roll into a cigar shaped rod, stick into open radiator. If it’s not blue/coolant coloured or dark thats not good so you’ve got to drain the oil and let it sit. Water obviously lighter than oil so if any appears more investigation needed. Will check the radiator, but at first glance the rad water does look brown and sludgey. Edging towards the head gasket solution. Thx Rob. Quote
TR4'er Posted June 4 Author Report Posted June 4 3 hours ago, trchris said: Hi Rob Agree with Rob if the oil on the dip stick looks good it’s likely the head gasket Chris 👍 Quote
TR4'er Posted June 4 Author Report Posted June 4 3 hours ago, John Morrison said: Could it be the ally plug in the head? John Hi john, pls excuse my ignorance - any details or references that I can chase up to find out what the "ally plug in the head" is. Sorry for not being on the same wavelength. Rob. Quote
John Morrison Posted June 5 Report Posted June 5 Rob, if you remove the rocker cover, you will see an alloy round plug a bout 25mm in diameter it is a tapered plug, you might be lucky and find it’s ‘Weeping’ John Quote
rcreweread Posted June 5 Report Posted June 5 25 minutes ago, John Morrison said: Rob, if you remove the rocker cover, you will see an alloy round plug a bout 25mm in diameter it is a tapered plug, you might be lucky and find it’s ‘Weeping’ John Except that would more likely lead to water in the oil, which isn't being pointed to. The oil seems to be mixing with the water, hence my bet would be the head gasket Cheers Rich Quote
Ralph Whitaker Posted June 5 Report Posted June 5 (edited) Plenty of evidence of water on the underside of that oil filler cap. As an easy first step I would be taking the rocker box off and checking the ally plug. Step 2 would be a compression test for me before jumping in to taking the head off. and I wouldn`t rely on checking the sump oil using the dipstick, water will settle to the bottom of the sump and as you draw the dipstick out it will get coated with the oil resting on top, I`d drain the oil and watch carefully for what comes out first Ralph Edited June 5 by Ralph Whitaker Quote
Steve-B Posted June 5 Report Posted June 5 11 hours ago, TR4'er said: Will check the radiator, but at first glance the rad water does look brown and sludgey. Edging towards the head gasket solution. Thx Rob. Rob, if there's any smell of oil in the radiator kitchen roll sample you have your verification oil & water are mixing somewhere... learned this when the head gasket on our Caterham failed! Quote
Ralph Whitaker Posted June 5 Report Posted June 5 1 hour ago, Steve-B said: Rob, if there's any smell of oil in the radiator kitchen roll sample you have your verification oil & water are mixing somewhere... learned this when the head gasket on our Caterham failed! Don`t think you need to worry about smelling it, it is quite clearly visible on the rad cap. Unless of course someone has put oil in the radiator by mistake, but theres still the water on the oil filler cap. Quote
Dic Doretti Posted June 5 Report Posted June 5 I have a 1949 Citroen with a very similar engine to a TR and I recently found water in the oil and assumed it was the head gasket or figure of 8 seals. I put off the job as the cylinder head has to come off to rectify either. When I got round to it I took the rocker cover off and found water on the top of the head under the rocker shaft so not the head gasket or seals but internal core plugs in the head the equivalent of the alloy plug in the TR head so an easy fix. Cheers Richard Quote
TR4'er Posted June 16 Author Report Posted June 16 Thanks for all your coments - taken on board. ust back from Hols, so will start tomorrow Wed 17th and will update with any developments. Thx again. Rob. Quote
PriceLes Posted June 17 Report Posted June 17 On 6/5/2026 at 6:35 AM, TR4'er said: "ally plug in the head" This is the factory plug in the cylinder head, not it applies to your situation based on previous replies. That plug can corrode from the inner side resulting in weeping (as I found) . It can be removed and tapped 3/4 NPT to take a brass hex plug. Quote
Z320 Posted June 17 Report Posted June 17 2 hours ago, PriceLes said: Hi ?, the leak sure is correct, no doubt. But the coolant on the surface and no oil visible is prepared? Ciao, Marco Quote
PriceLes Posted June 17 Report Posted June 17 (edited) 5 minutes ago, Z320 said: Hi ?, the leak sure is correct, no doubt. But the coolant on the surface and no oil visible is prepared? Ciao, Marco The weep picture was in the car with the rocker cover removed. Found when checking the valve clearances which were IN 0.005” and EX 0.002” (DPO<) Edited June 17 by PriceLes Quote
Hamish Posted June 17 Report Posted June 17 5 hours ago, PriceLes said: This is the factory plug in the cylinder head, not it applies to your situation based on previous replies. That plug can corrode from the inner side resulting in weeping (as I found) . It can be removed and tapped 3/4 NPT to take a brass hex plug. On my last engine I had this weeping from the head screw in core plug. It was mid race season with no real time to fix or rush the fix escalating as these things do so I went round it with a sharp small punch and it worked well enough that I didn’t bother replacing it. Quote
RogerH Posted June 17 Report Posted June 17 Hi Hamish Most of the 'Radweld' type aditives work very well for such leaks Roger Quote
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